Abstract: Bispecific antibodies have shown significant efficacy in tumor therapy due to their dual targeting ability, but the complexity of their structure leads to the production of various process-related impurities such as host cell proteins, host cell DNA, and Protein A, and product-related impurities such as semi antibodies, 3/4 antibodies, homodimers, bispecific antibodies lacking one Fab arm, and aggregates during the manufacturing process. This paper systematically summarizes downstream purification strategies for dual antibodies, including affinity chromatography, deep filtration, hydroxyapatite chromatography, hydrophobic interaction chromatography, ion exchange chromatography, and multimodal chromatography, to efficiently remove various impurities and provide theoretical support for the purification of dual antibodies.