HgCdTe avalanche photodiodes (HgCdTe APDs) have broad application prospects in low photon detection fields such as active / passive imaging,lidar,wavefront sensing and photon counting due to its excellent performance of high gain,high bandwidth,high quantum efficiency and low noise.Foreign research institutions have conducted in depth research in this field by adopting different technical routes.In this paper,the principle and structure of APD are described.The research progress and application of HgCdTe APD abroad in recent years are mainly introduced.The research achievements of domestic research institutions in simulation and device preparation of HgCdTe APDs are summarized.