In the field of sewage treatment, the use of aluminum salts and iron salts as chemical phosphorus removal agents is of great significance for improving the efficiency of biological phosphorus removal. This study comprehensively discusses the impact of chemical phosphorus removal agents on the biological phosphorus removal process, focusing on the analysis of the action mechanisms of aluminum salts and iron salts and their impact on biological phosphorus removal performance. By reviewing the existing research results, the current problems in understanding the impact mechanism of chemical agents on biological phosphorus removal are pointed out, and the directions and suggestions for future research are put forward. This aims to provide theoretical support and practical guidance for the optimization of the synergy between biological and chemical phosphorus removal in sewage treatment plants.