The investigation of defects in perovskite crystals is essential to promote the development of perovskite solar cells. The defects result in non-radiative recombination as well as the deterioration of device stability. To reduce the impact of material defects on photovoltaic performance, it is necessary to deeply understand the types of perovskite film defects and the routes of suppression methods. According to electronic characteristics, defects can be divided into electron-rich and electron-deficient defects. Based on Lewis acid-base theory, electron-rich defects can be passivated by Lewis acid, and electron-deficient defects can be passivated by Lewis base or ionic liquids. These passivation additives can be added during the formation of perovskite film, or used to post-treat the surface of the films. This review summarized the defect passivation cases reported in recent years to visually present design strategies of additives and the effects of defect passivation on photovoltaic performance. Finally, developing multi-functional passivators, large-area passivation strategy and advanced charge transport layer were proposed for future perspective. This review is expected to promote the development of perovskite solar cells in the future.