Recombinant Anti-pre S2 protein x Anti-S protein Bispecific Antibody (F(ab')2-scFv2) is designed to be expressed as two chains combined via a hinge region. The scFv of the anti-pre S2 protein specificity is fused to the C terminus of the anti-S protein Fab fragment, or vice versa. This format comprises four binding sites (two same scFv regions and two same Fab fragments), two for each antigen. This BsAb can bind two antigens simultaneously. It is designed for the research of HBV infection therapy.