The invention provides an anti-human CD47 and anti-human SIRP alpha bispecific antibody. The anti-human CD47 and anti-human SIRP alpha bispecific antibody contains a first antigen binding domain with specific binding of the CD47 and a second antigen binding domain with the specific binding of the SIRP alpha, and each of the first and second antigen binding domains comprises a pair of antibody heavy chain variable domain (VH) and antibody light chain variable domain (VL) the first antigen binding domain is the antibody variable domain capable of realizing the specific binding of the CD47 the second antigen binding domain is the antibody variable domain capable of realizing the specific binding of the SIRP alpha. A preparation method mainly comprises the steps of synthesizing a cDNA (complementary deoxyribonucleic acid) sequence encoding the antibody inserting the cDNA sequence into a tool carrier to construct an expression carrier expressing the expression carrier in host cells, and separating and purifying the expressed bispecific antibody. The anti-human CD47 and anti-human SIRP alpha bispecific antibody provided by the invention is used for preparing medicines for treating human cancers.
