At present, the reform of China's judicial system and working mechanism is progressing steadily. Reform is the premise of development, the basic character of reform is innovation, and the reform and development of criminal evidence system is no exception. Last year, the Supreme People's Court, the Supreme People's Procuratorate and other five departments jointly formulated and issued the Provisions on Several Issues Concerning the Examination and Judgment of Evidence in Handling Death Penalty Cases and the Provisions on Several Issues Concerning the Exclusion of Illegal Evidence in Handling Criminal Cases (hereinafter referred to as the "Two Provisions on Criminal Evidence"), which are the products of the reform of China's criminal evidence system and reflect the development direction of China's criminal evidence system to some extent. However, we should be soberly aware that the reform, development and perfection of the criminal evidence system is not only a long process, but also a systematic project. We should make a comprehensive and long-term plan from a higher angle and choose the right path to continuously promote it. The author believes that the reform must be based on the concept renewal and the system innovation, which is the basic path of all reforms. However, from a practical point of view, concept renewal and system innovation complement each other, and they are mutually causal. As far as the reform of criminal evidence system is concerned, it is very important to update the concepts, such as the presumption of innocence, human rights protection and procedural justice, which will greatly influence the process and quality of the reform. However, the construction of new criminal evidence principles and systems may be more practical and should become a top priority. When the criminal evidence system is self-contained and forms a complete legal norm, it can not only make criminal judicial activities have laws and rules to follow, but also greatly affect the behavior consciousness of judicial subjects, and the concept change is among them. From the perspective of the above two provisions on criminal evidence, this paper systematically expounds the contents and requirements of system innovation from the aspects of evidence principle, evidence collection, proof, cross-examination and authentication, and strives to explore a correct path for the reform and development of criminal evidence system with China characteristics. I. On Establishing Three Principles of Criminal Evidence The principle of criminal evidence is a guideline that must be followed in the reform and development of the criminal evidence system. Since the Second World War, the reform of criminal justice system in various countries has taken democracy, civilization and rule of law as the basic orientation, and generally pursued three principles in evidence system: presumption of innocence, evidence judgment and procedural rule of law. It can be said that these three principles have become the cornerstone of modern criminal evidence and even the whole criminal procedure system. The first is the principle of presumption of innocence. The idea of presumption of innocence originated from ancient Roman law. The first person who made a complete statement on the connotation of presumption of innocence in modern times was Beccaria, an Italian enlightening criminal jurist. In his book On Crime and Punishment, he wrote: "Before the judge decides, a person cannot be called a criminal. As long as it can't be concluded that he has violated the contract that gives him public protection, society can't cancel his public protection. " "If the crime is uncertain, an innocent person should not be tortured, because, according to the law, his crime has not been proved." [1] As the result of the French Revolution, the Declaration of Human Rights in 1789 was the first legal document to make a classic statement on the principle of presumption of innocence. In the development of more than 2 years, the connotation and extension of the presumption of innocence have been continuously expanded, and in many countries, the principle of criminal procedure has risen to the constitutional principle, and the value of human rights protection has become more and more prominent. "The principle of presumption of innocence is the iron rule of the Criminal Procedure Law and the most fundamental principle for implementing the protection of human rights." [2] As the principle of criminal evidence, the value of presumption of innocence is mainly reflected in its derivation rules. There are three derivative rules recognized by academic circles: (1) In criminal proceedings, the burden of proving the defendant's guilt is borne by the accuser, and the defendant is not obliged to prove his innocence; (2) The defendant has the right to refuse to state, and cannot force the defendant to testify against himself, nor can he take the defendant's silence as the basis of guilt; (3) When there is doubt about whether the defendant is guilty or not and the severity of the crime and punishment, an explanation should be made in favor of the defendant. It is generally believed that the principle of presumption of innocence was established in Article 12 and Item 3 of Article 162 of China's revised Criminal Procedure Law in 1996, but the contents of the provisions are not complete, especially the above three derivative rules, which are not only lacking in legal provisions, but even have contradictory provisions such as "the defendant should truthfully state". Because of this, the author believes that the reform of the criminal justice system is not complete in the implementation of the principle of presumption of innocence, so that in the later judicial practice, the phenomenon of violating the principle of presumption of innocence still occurs from time to time, and extorting confessions by torture is repeatedly prohibited, which in serious cases leads to unjust, false and misjudged cases. The case of Zhao Zuohai, Henan Province is a typical example. The promulgation of "Two Provisions on Criminal Evidence" makes up for the deficiency of China's criminal evidence system to a certain extent, but these two provisions are only a remedy and cannot solve the whole problem. One is that there are still many reservations and accommodation in the contents of the two provisions; Secondly, it has a low rank of validity, and it only belongs to general normative documents, and there is no legal enforcement. Therefore, we hope that in the future revision of the criminal procedure law, we can seriously reflect on the positive and negative experiences and lessons, make more accurate and complete provisions on the principle of presumption of innocence and its derivative rules, and truly play its important role in guiding the whole criminal evidence system. The second is the principle of evidence adjudication. The so-called principle of evidence judgment means that in criminal proceedings, the defendant must be found guilty and sentenced on the basis of evidence, and a guilty judgment cannot be made without evidence or insufficient evidence. According to the principle of judging by evidence, in criminal proceedings, if the defendant cannot be proved guilty, it means that he is proved innocent. As we all know, evidence is the cornerstone of litigation. In criminal proceedings, all litigation activities are carried out and promoted around evidence, from filing, investigation, prosecution to trial. Any case happened in the past, and after the passage of time, the determination of the facts of the case can only rely on evidence. Moreover, evidence alone is far from enough, and it must meet the full and definite requirements, otherwise a guilty verdict that conforms to the principle of evidence judgment cannot be made. It should be said that since the promulgation and implementation of China's criminal procedure law in 1979, the spirit of the principle of evidence adjudication has been reflected to a certain extent in the norms of guiding principles, litigation procedures and basic systems, but we have not publicly established the principle of evidence adjudication, and there are many unscientific and imperfect provisions. Fortunately, Article 2 of the Provisions on Several Issues Concerning the Examination and Judgment of Evidence in Handling Death Penalty Cases (hereinafter referred to as the Provisions on Evidence in Death Penalty Cases), one of the two provisions on criminal evidence, clearly puts forward the requirement that "the facts of a case must be based on evidence", which is a deepening of the principle of "taking facts as the basis and taking law as the criterion" in the Criminal Procedure Law and a historic progress. I hope that in the future revision of the criminal procedure law, the principle of evidence adjudication can be formally established in the basic law and ensured to be followed in all cases. The third is the principle of procedural rule of law. The principle of procedural rule of law requires that the procedural construction of criminal proceedings should not only have a complete legal form, but also fully embody the spirit of democratic, civilized and just procedural rule of law. In the construction of criminal procedure system, the standard of evidence system is its soul and core. It can be said that without modern evidence system, there would be no democratic, civilized and legal proceedings; In other words, the litigation procedure is just a beautiful shell in the form of legal system. On the other hand, the principle of procedural rule of law is of great significance, which restricts the exercise of judicial public power and protects the basic rights of the prosecuted from infringement. This requires judicial personnel to strictly abide by legal procedures when collecting, fixing, preserving, examining and judging evidence. Serious procedural violations should not only hold judicial workers personally responsible, but also lead to the failure of litigation and the defendant being acquitted. It should be said that the promulgation of "Two Provisions on Criminal Evidence" has made up for the deficiency of evidence legislation in China in terms of excluding illegal evidence and examining and judging evidence, but the contents and functions of these two provisions are still limited, and we can't let them bear unbearable weight. We hope that in the future revision of the Criminal Procedure Law, the principle of procedural rule of law can be established, and the modern criminal procedure and criminal evidence system with China characteristics can be constructed and improved according to the spirit of this principle. According to the inherent logical relationship of proof activities, judicial proof mainly includes four links: obtaining evidence, presenting evidence, cross-examination and authentication. The construction of criminal evidence system and judicial proof activities must follow the three principles of criminal evidence. Only under the macro guidance of these three principles can we establish a unified system of evidence collection, proof, cross-examination and authentication. In the four successive judicial proof links mentioned above, each link is the basis and premise of the latter, and the latter is the deepening and application of the former, which is organically connected and interlocking, forming a chain of evidence application. Criminal evidence must be screened and screened in accordance with the procedures prescribed by law, and finally it can be used as the basis for determining the facts of the case. The reform of criminal evidence system should not only focus on the construction of basic principles, but also be implemented in the specific system of obtaining evidence, presenting evidence, cross-examination and authentication. Based on the three principles of presumption of innocence, evidence judgment and procedural rule of law, the following will specifically elaborate on the system innovation of evidence collection, proof, cross-examination and authentication. Second, the system innovation of evidence collection is the first link of judicial proof and the first door that evidence needs to open when it enters the litigation field. Criminal evidence, as the basis for determining the facts of a case, needs to go through a transformation process from a natural state to a legal state, and the evidence that is not included in the litigation track is not a problem that usually needs to be studied by evidence law. According to the requirements of the three principles of criminal evidence, if the evidence is not timely, sufficient, standardized or even illegal, or the evidence cannot be obtained, it may seriously affect the normal operation of the lawsuit, and even lead to the subsequent lawsuit being unable to continue at all, just like "a clever woman can't cook without rice." The process of evidence entering the litigation track is the process of collecting evidence by all parties in litigation. Article 43 of China's Criminal Procedure Law stipulates: "Judges, prosecutors and investigators must collect all kinds of evidence that can prove the guilt or innocence of criminal suspects and defendants and the seriousness of the crime according to legal procedures." Although the parties have the right to actively collect evidence, the effect in judicial practice is not ideal because of their weak ability to collect evidence and lack of adequate guarantee in the system, so the collection of evidence mainly depends on the public security and judicial organs. The process of collecting criminal evidence is mainly in the investigation stage of a case, and investigation activities are very important for the development of a criminal case. Whether the evidence is solid, standardized and legal depends mainly on the work in the investigation stage. Based on this, this part focuses on the related issues of investigation and evidence collection. Although the provisions on evidence collection system in China's criminal procedure law and related judicial interpretations are relatively scattered, they have gradually become systematic. Articles 43 and 45 of the Criminal Procedure Law stipulate the evidence collection system in principle. The former stipulates that public security judicial personnel must collect all kinds of evidence that can prove the guilt or innocence of criminal suspects and defendants and the seriousness of the crime in accordance with legal procedures; The latter stipulates that the public security and judicial organs have the right to collect and obtain evidence from relevant units and individuals, and relevant units and individuals shall provide evidence truthfully. Specific to the collection of each kind of evidence, the Criminal Procedure Law and relevant judicial interpretations stipulate the relevant issues of collecting evidence through various investigation measures, including interrogation of criminal suspects, questioning of witnesses, inquest, inspection, search, seizure and identification. In addition, the relevant judicial interpretation also provides for some important rules of evidence. For example, the Supreme People's Court's "On the implementation of <; Criminal Procedure Law of the People's Republic of China >: Article 53 of the Interpretation of Several Issues stipulates the priority rule of original evidence, and article 61 stipulates the exclusion rule of illegal verbal evidence. The newly formulated "Two Provisions on Criminal Evidence" has greatly promoted the development of criminal evidence principles, such as the principle of judging evidence and the principle of procedural rule of law. Not only have these two important principles been explicitly established for the first time, but their spirit and requirements have been implemented in a series of problems of examining and judging evidence and excluding illegal evidence, and a system of three principles of criminal evidence in China has been initially established. Of course, due to the rank of documents and other factors, the implementation and implementation effect of the Two Provisions on Criminal Evidence may be affected to some extent. In the future revision of the Criminal Procedure Law, it is necessary to further improve the criminal evidence collection system in the form of basic laws. Generally speaking, China's criminal evidence collection system has been relatively rich and increasingly perfect, and the existing achievements have enhanced our confidence in continuing to promote the reform of the criminal evidence system, but the problems existing in the evidence collection system can not be ignored. First of all, there are still some gaps or deficiencies in the legal norms of evidence collection system in legislation. What is more prominent is that the procedure of collecting evidence through special investigation means in criminal proceedings is not standardized enough or lacks effective supervision and restriction mechanism. Take wiretapping as an example, the Criminal Procedure Law does not provide for this, although the National Security Law and the People's Police Law stipulate that technical reconnaissance measures can be taken after strict approval procedures because of "the need to detect acts endangering national security" or "the need to investigate crimes". However, these regulations are obviously too principled. "There is neither a clear scope of cases in which interception can be applied, nor a corresponding regulation on how to use it. This lawless state is unfavorable for the correct use of secret interception to detect crimes or the protection of the rights of the eavesdropper." [3] Secondly, there are still some acts of not obtaining evidence according to law in judicial practice. The casting of unjust, false and wrong cases is often caused by problems in the application of evidence, especially in the collection of evidence, such as extorting confessions by torture, asking for confessions by name, and misrecognition. To solve the problems such as irregular and illegal behavior of obtaining evidence, we not only need complete legislation, but more importantly, we should abide by the law, handle cases strictly according to law, and implement the existing legal norms into specific functions and powers. Finally, in theoretical research, the research on the evidence system is still relatively backward compared with the litigation system, which can not meet the needs of judicial practice, and many problems of evidence and proof are not mature enough, which still need further discussion. The author believes that the existence of the above problems is the result of a variety of factors, and the reform and improvement of the evidence collection system in the next step must also be comprehensively implemented and promoted. In view of the outstanding problems in the practice of evidence collection, the next step seems to focus on improving the ability of evidence collection and standardizing the behavior of evidence collection: First, improving the ability of investigation organs to collect evidence. From the point of view of accurately punishing crimes, we should constantly improve legislation, build a scientific evidence collection system, provide more legal investigation means for investigation activities, and clearly define the legal attributes of some evidence materials obtained through special investigation means and special technologies, so as to comprehensively improve the ability of investigation organs to collect evidence. First, improve the collection system of legal evidence types. To effectively improve the ability of investigation organs to collect evidence, it is necessary to regulate and guide them positively in legislation, and to guarantee them with punitive consequences from the opposite side. To improve the collection system of various types of evidence, we should not only stipulate the legality and standardization of evidence collection methods and procedures, but also stipulate the consequences of not collecting according to law. The second part of the Provisions on Evidence in Death Penalty Cases refines the contents that should be emphatically examined for each kind of evidence, and stipulates the consequences of irregular and illegal evidence collection. If there are defects in the form of evidence, the principle of discretionary exclusion shall be implemented. For example, article 14 procedures and methods for collecting witness testimony.