Novel bispecific antibody and purpose thereof

The invention provides a novel bispecific human IgG1 antibody, which comprises two kinds of Fc fragments with the same hinge regions, wherein the amino acid sequence of the hinge region is SEQ ID NO:1 or SEQ ID NO:28; the 216th to 230th site sequences in a natural human IgG1 antibody constant region are replaced. The amino acid position of the antibody constant region is determined according to EU numbering. In addition, the invention also provides a purpose of the bispecific antibody.