Recombinant Anti-FGFR1 x Anti-KLB Bispecific Antibody (scFv-CH1/CL) is designed to be expressed as two chains. One scFv from an anti-FGFR1 antibody variable domain is fused to CH1 and the other scFv from an anti-KLB antibody variable domain fused to CL, or vice versa. And the CH1 and CL domains are linked covalently via a natural disulfide bond. This BsAb can bind two factors simultaneously and act as mimetic hormone (FGF21) . It is designed for the research of Type 2 diabetes therapy.