Abstract: The small bodies retain the original elements of early solar system,and may contain important clues to the origin of the earth's life and water. They are living fossils for studying the origin and evolutionary history of the solar system. Asteroid exploration has become research hotspots of international deep space exploration in recent years. The process of small bodies exploration is briefly summarized, and the research and development of asteroid exploration is reviewed, as well the key technologies of asteroid missions. Based on the deep space exploration capability of China, some suggestions are put forward to carry out future asteroid exploration.