Abstract: High-performance metal materials are often inseparable from better processing technology, and diffusion bonding technology plays an important role in the field of metal materials. The basic principle of diffusion bonding technology is introduced, the solid state diffusion process of materials is expounded, and the advantages compared with traditional bonding methods are expounded. The influencing factors of diffusion bonding are discussed,including process parameters, element diffusion, interfacial bonding strength and fracture mechanism, especially the influence of temperature, pressure and holding time on joint strength. The applications of diffusion bonding in aerospace and nuclear energy are discussed, and the further research direction of diffusion bonding is put forward.