Faced with the heavy obstruction of the feudal die-hards in the Qing court, Li Hongzhang once plausibly put forward that "it is sacred to talk about westernization today." In his view, in the process of pursuing self-improvement, we must adhere to the general program of westernization, that is, in the environment of being surrounded by foreign powers and increasing foreign aggression, we should make maximum use of the diplomatic means of "controlling foreign countries" to win as much peaceful time as possible for China's westernization-self-improvement. To this end, he spent his whole life as a diplomatic expert and handled many important diplomatic negotiations. On July 29th, the decade of Tongzhi (187 1), Li Hongzhang signed the Sino-Japanese Reconciliation Ordinance on behalf of China, which is a treaty of equality and mutual benefit. But from the attitude of the Japanese in the process of signing the contract, Li Hongzhang saw that Japan "will be China's elbow and armpit in the future". Sure enough, in the 13th year (1874), the Japanese army invaded Taiwan Province, and Li Hongzhang actively supported the Qing government to send Shen Baozhen as an imperial envoy to lead a fleet to visit Taiwan Province Province, and transferred 6,500 troops of Tang Dingkui's Huai Army stationed in Xuzhou to Taiwan Province Province in batches. Although the incident was temporarily subsided by signing the Sino-Japanese Treaty on Taiwan Province Affairs, Japan later annexed Ryukyu in the fifth year of Guangxu (1879). Before and after negotiations with Japan, Li Hongzhang also signed the Sino-Peruvian Trade Treaty in the 13th year of Tongzhi (1874). In the second year of Guangxu (1876), the Sino-British Yantai Treaty was signed with Britain. The former aims to protect workers in China; The latter is a serious negotiation between China and Britain caused by the "Ma Jiali case". Under the threat of the British envoy Wade raising the flag to declare war, Li Hongzhang skillfully used international law to save the diplomatic relations. At his suggestion, the Qing government sent Guo Songtao to England to apologize, and Guo became the first foreign minister of China. However, the treaty also allowed British people to enter Tibet by opening four trading ports, namely Yichang, Wuhu, Wenzhou and Beihai, which damaged China's sovereignty. In the ninth year of Guangxu (1883), the Sino-French war started in Vietnam, and the Qing court ordered Li Hongzhang to co-ordinate the border war. Li Hongzhang believes that "the coastal defense soldiers in all provinces are single-handed, and the navy has not been trained, so it is impossible to underestimate the European powers." He first signed the Pauli Agreement with Bao Hai, the French ambassador to China, and then failed to negotiate with the French ambassador to Japan. The war entered a stalemate, Cixi reorganized the Ministry of War, and peaceful public opinion gradually rose. In Guangxu 10 (1884), Li Hongzhang signed the Li Fu Agreement with French representative Flouno on April 17. In May, with the French attack on lang son, the agreement was torn up again. It was not until the Qing army won the battles in Guangxi and Taiwan Province Province respectively that Li Hongzhang finally signed the Sino-French Vietnam Treaty with French representative Badeno, thus ending the war. France gained the privilege of "protecting" Vietnam and opened the Sino-Vietnamese border to France. Therefore, it is called "invincible in law, unbeaten in China, and defeated." Li Hongzhang was the most outstanding diplomat in the late Qing Dynasty. He devoted the rest of his life to China's diplomatic career. Although he signed almost all the traitorous treaties, he did his best as a diplomat in the international environment at that time. All the foreign relations negotiations failed because of China's decadent political system, backward economic base and weak international status at that time, and all this was ultimately due to the influence of the Manchu royal family headed by Cixi. In order to hide their incompetence, these people can only blame Li Hongzhang, a servant who works directly. During the nearly 100 years from the Second Opium War to the founding of People's Republic of China (PRC), generations of China diplomats, led by Li Hongzhang, made use of the complex international environment to do everything possible to safeguard the national spirit of the Chinese nation and the general integrity of China's national system, so that China was not completely colonized like South Asian countries, which laid a solid foundation for the rise and rejuvenation of the Chinese nation.