Abstract: The hypervelocity impact of the micro-meteoroid & orbital debris (MMOD) threatens the safety of on-orbiting spacecraft, leading to functional degradation or even mission failure. The risk assessment is an effective approach for checking and verifying the survivability of spacecraft under the MMOD hypervelocity impact. This paper analyzes the characteristics and the mechanism, as well as the damage behavior of the MMOD hypervelocity impact to spacecraft, and reviews the development of the spacecraft risk assessment in the MMOD environment, as well as the development trends of key technologies, including the impact susceptibility and the vulnerability of spacecraft structure and inner parts, and makes suggestions on building China’s spacecraft risk assessment system.