Abstract: With the expansion of human space exploration, planetary protection has become an important issue for future human deep space exploration. In this paper, starting from the concept of planetary protection, and the research background and the research activities of the United States, Europe, Russia and other countries are introduced, involving the policy making, standard specification, pollution prevention and control, technical system and other aspects.All stages of manned deep space exploration are possible sources of pollution, and must carry out the related protection and the protection technology research. An in-depth study of international planetary protection policies, regulations and technical systems is of great significance for China to carry out relevant studies in the future.