MEMS micromirror, a novel micro-optical-electro-mechanical system, can accomplish optical modulation at microscale and has been widely applied in the fields of photoelectric communication, medical imaging, civil projection, radar detection, etc. In recent years, MEMS LiDAR with micromirrors as core component is expected to become one of the more competitive autonomous sensors due to its advantages such as small size and low power consumption. However, given the specificity of in-vehicle applications, various reliability problems of MEMS micromirrors in complex multi-physical field coupled environments such as temperature and humidity, electromagnetic, vibration and shock have seriously restricted the engineering applications of MEMS LiDAR. Based on the reliability research of MEMS micromirrors, this paper reviews the complex failure forms and failure mechanisms such as delamination warpage, fracture, pull-in and short circuit burnout under extreme environments such as high frequency vibration, temperature & humidity cycling and electromagnetic coupling. We also summarize the common dynamics modelling theories and control methods of MEMS micromirrors and discuss the main challenges and development trends of MEMS LiDAR standardization.