Recently, organic–inorganic hybrid metal halide perovskite (O-IHMHP) has been diffusely used in solar cells due to its remarkable photoelectric property and inexpensive film-forming process. Since organic–inorganic hybrid metal halide perovskite solar cells (O-IHMHPSCs) were introduced in 2009, their photoelectric conversion efficiency has been increased to 25.2%, and their lifespan has been extended to tens of thousands of hours. However, due to processing factors, defects consist in the interfaces of O-IHMHP with the electron transport layer and the hole transport layer. To improve the stability and property of O-IHMHPSCs, these defects must be addressed; to do so, passivation is commonly applied at the interface. This work reviews research on the interface passivation of O-IHMHPSCs. Here, the passivation mechanisms of different additives on the interface defects of O-IHMHP films are analyzed, their impacts on the stability and property of O-IHMHPSCs are compared, and their roles in O-IHMHPSCs are summarized. Finally, the research and development trends of the defect passivation of O-IHMHPSCs are discussed.