China's first invention in ancient times: meridian theory is the only traditional science in ancient China that has not been replaced by modern science: traditional Chinese medicine; In the traditional medicine of all countries and nationalities in the world, Chinese medicine has the longest duration and the most full development. Moreover, this ancient science still shows strong vitality, continues to develop and advance, and is paid more and more attention by the world medical and scientific circles. This is because Chinese medicine has its own independent and complete theoretical system and its own unique and effective diagnosis and treatment methods. Meridian theory is one of the important basic theories in China's medical theory system. In the early 1990s, Professor Zhu Zongxiang, head of the Meridian Research Group of the Institute of Biophysics of the Chinese Academy of Sciences and director of the Beijing Meridian Research Center, after 20 years of painstaking research and scientific argumentation, clearly pointed out: China had the smuggling theory before the four ancient inventions, which was the first great invention in China. Meridian is the general name of meridian. Meridians, such as paths, are longitudinal trunk lines, including the twelve meridians, Qijing Eight Veins and the twelve meridians. Collaterals such as nets are horizontal branches, including fifteen-branch collaterals, sun collaterals and floating collaterals; Besides, there are twelve tendons and twelve skins. They cross each other to form a complete network system, which connects the viscera, organs, pores, bones and muscles of the human body into a unified organic whole. The twelve meridians refers to lung meridian of hand Taiyin, pericardium meridian of hand Jueyin, heart meridian of hand Shaoyin, large intestine meridian of hand Yangming, triple energizer meridian of hand Shaoyang, small intestine meridian of hand Taiyin, spleen meridian of foot Taiyin, liver meridian of foot Jueyin, kidney meridian of foot Shaoyin, stomach meridian of foot Yangming, gallbladder meridian of foot Shaoyang and bladder meridian of foot Taiyang. They are the main channels of qi and blood circulation, which are directly related to the internal organs. The eight strange meridians refer to Ren, Du, Chong, Dai, Yin, Yang, Yin Wei and impotence, and have the functions of controlling, connecting and regulating the twelve meridians. The twelve meridians, which originated in the twelve meridians, has the function of strengthening the connection between the two meridians in the twelve meridians. Meridian 15 refers to one of the twelve meridians, Renmai and Dumai, which, together with the spleen collaterals, has the function of strengthening the connection between meridians on the exterior and interior of the body and infiltrating qi and blood. Solar collaterals refer to tiny collaterals; Floating collaterals refer to collaterals emerging on the body surface. The twelve meridians refers to the system in which the twelve meridians's qi gathers, gathers, disperses and binds to the muscles and joints, which has the function of connecting the joints of limbs. Twelve Skin refers to the reflection of the twelve meridians's functional activities on the body surface. The discovery of human meridian system is closely related to the invention of acupuncture. As early as more than 4,000 years ago, our ancestors had discovered in their work that stimulating certain parts of the human body (that is, "acupoints") with sharp tools such as stone tablets could cure diseases, thus giving birth to acupuncture. With the improvement of production level, stone needles gradually evolved into bone needles and bamboo needles, and finally metal needles were produced. Due to the toughness of metal and the improvement of needle-making technology, acupoint selection is more accurate, and the phenomenon of induction along meridians during acupoint selection makes people gradually discover the meridian system of the whole body. Huangdi Neijing in the 4th century BC and Nanjing in the 2nd century BC systematically summarized the predecessors' understanding of the phenomenon of human meridians, and put forward a complete theory of meridians: meridians are distributed in all parts of the human body, and are responsible for transporting the whole body's qi and blood and communicating with the inside and outside of the human body; Meridians and collaterals are not only distributed on the body surface, but also enter the body to communicate with the viscera, and run endlessly. Because every yin meridian belongs to a dirty organ and is connected with a viscera; Each yang meridian belongs to a zang-fu organ, which is connected with a zang-fu organ, so that the limbs of the whole body are closely connected with the zang-fu organ. The diseases referred to by each meridian are directly related to its running direction and its viscera. In this way, the meridian theory is of special significance for explaining the physiological function and pathological changes of human body and guiding the diagnosis and treatment of diseases. It is also the theoretical basis of acupuncture. So it is the first thing that Chinese medicine learners should be familiar with. Zhang Zeng, a medical scientist in Jin and Yuan Dynasties, said, "If the twelve meridians doesn't recite, it's wrong to open his mouth." This is a wise saying. The meridians are invisible and intangible. Even in today's highly developed modern science and technology, modern scientific instruments are still invisible. So, how the ancients discovered it more than 2000 years ago is still a mystery. However, the meridians do exist objectively, which has become a "magic weapon" for doctors in China to diagnose and treat various diseases. For thousands of years, human knowledge has accumulated over time and science and technology have developed by leaps and bounds. However, people can only study, verify and apply the meridian theory, but they are unable to supplement, modify and develop this theoretical system. On the one hand, this shows the wisdom of our ancients, on the other hand, it also exposes the shortcomings of modern science and technology. How to use modern scientific theories and methods to study meridian phenomena, reveal the essence of meridians, and make them better serve human health is a major issue before the vast number of scientific and technological workers.