Recombinant Anti-pre S2 protein x Anti-S protein Bispecific Antibody (scDiabody-Fc) is a fusion protein of two scDiabodies with an Fc region. In single-chain Diabodies, an additional connecting linker is introduced between chains of the anti-pre S2 protein/anti-S protein diabody. The scDiabody with two specificities is further fused to the Fc domain to form BsAb with 2+2 antigen-binding valency. This BsAb can bind two antigens simultaneously. It is designed for the research of HBV infection therapy.