Bispecific antibody capable of resisting human epidermal growth factor receptor 2 (HER2) and human insulin-like growth factor-IR (IGF-IR), and preparation method and applications thereof

The invention provides a bispecific antibody capable of resisting human epidermal growth factor receptor 2 (HER2) and human insulin-like growth factor-IR (IGF-IR), and a preparation method and applications thereof. The bispecific antibody comprises a first antigen binding domain used for specific binding of HER2, and a second antigen binding domain used for specific binding of IGF-IR; the first antigen binding domain and the second antigen binding domain both comprise an antibody heavy chain variable structural domain (VH) and an antibody light chain variable structural domain (VL); the first antigen binding domain is an antibody variable structural domain capable of realizing specific binding with HER2; and the second antigen binding domain is an antibody variable structural domain capable of realizing specific binding with IGF-IR. The preparation method comprises following steps: synthesis of cDNA sequences used for coding the bispecific antibody; the cDNA sequences are inserted into a carrier for construction of an expression vector; expression of the expression vector is realized in host cells, and the bispecific antibody obtained by expression is separated and purified. The bispecific antibody can be used for preparing medicines used for treating human cancer, especially human breast cancer.