Recombinant Anti-TG x Anti-TPO Bispecific Antibody (Fab-Fv) is designed to be expressed as two polypeptide chains. The heavy chain Fd fragment and light chain of an anti-TG antibody are fused with the VL and VH domains of an anti-TPO antibody respectively. It can form natural in vivo heterodimerization. This BsAb can bind two antigens simultaneously and block the synthesis of thyroid hormones. It is designed for the research of Autoimmune thyroid disease therapy.