Feynman developed the method of expressing quantum amplitude by path integral in the 1940s, and put forward a new theoretical form, calculation method and renormalization method of quantum electrodynamics in 1948, thus avoiding the divergence difficulty in quantum electrodynamics. Feynman diagram was first put forward by Feynman in the late 1940s. It is used to describe the interaction between fields and can simply reflect the essence of the process. Feynman diagram has long been widely used. It is still the basic expression of electromagnetic interaction in physics. In addition to his outstanding contribution to quantum electrodynamics, Feynman also established a mathematical theory to solve the phenomenon of liquid helium superfluidity. Later, he and Murray gherman did some basic work in the field of weak interaction, such as β decay. Feynman played an important role in the development of quark theory, and he proposed a straton model of high-energy proton collision process.