Deep space communication is an essential guarantee for the implementation of deep space explorations. Laser communication has the characteristics of high data rate, small size, light weight and low power consumption, and has become the main trend of the future development of deep space communication. In this paper, the development status and trends of deep space optical communication system are summarized, and the composition and key technologies of deep space optical communication system are analyzed. On this basis, some suggestions for the development of deep space optical communication in China are given in terms of future technology development, networking planning, standardization and ecology evolution, demonstration and verification.