Recombinant Anti-BAFF x Anti-B7RP1 Bispecific Antibody (IgG-Fv) is formed by an Immunoglobulin G (IgG) and a fragment variable Fv region, in which the Fc of IgG is engineered by KIH. The Fv region of an anti-BAFF antibody variable domain is fused to the C terminal of an IgG of anti-B7RP1 antibody, or vice versa. The format retains desired characteristics of intact antibodies. This BsAb can bind and inactivate two ligands simultaneously. It can inhibit B cell survival and T cell costimulation. It is designed for the research of Systemic lupus erythematosus (SLE) therapy.