Perovskite solar cells (PSCs) have shown significant advancements in power conversion efficiency (PCE) over the past decade, but challenges remain in terms of photoelectric conversion efficiency and long-term stability. Defects in perovskite materials are a major factor affecting film quality and performance. This review discusses the types of defects in perovskite materials and their impact on device performance, as well as various additives used to passivate these defects. Additives include ionic compounds, organic molecules, and polymers. Ionic compounds, such as alkali metal ions and anions, can passivate point defects and grain boundary defects. Organic molecules, including organic ammonium salts, Lewis acids, and Lewis bases, can effectively passivate defects and improve film quality. Polymers, particularly those with long-range ordered structures, provide persistent defect passivation under operational conditions. The review highlights the effectiveness of these additives in enhancing PCE and stability, offering guidance for future research and development in PSCs.Perovskite solar cells (PSCs) have shown significant advancements in power conversion efficiency (PCE) over the past decade, but challenges remain in terms of photoelectric conversion efficiency and long-term stability. Defects in perovskite materials are a major factor affecting film quality and performance. This review discusses the types of defects in perovskite materials and their impact on device performance, as well as various additives used to passivate these defects. Additives include ionic compounds, organic molecules, and polymers. Ionic compounds, such as alkali metal ions and anions, can passivate point defects and grain boundary defects. Organic molecules, including organic ammonium salts, Lewis acids, and Lewis bases, can effectively passivate defects and improve film quality. Polymers, particularly those with long-range ordered structures, provide persistent defect passivation under operational conditions. The review highlights the effectiveness of these additives in enhancing PCE and stability, offering guidance for future research and development in PSCs.