Recombinant Anti-TG x Anti-TPO Bispecific Antibody (IgG(L)-scFv) is formed by an IgG and two scFv moieties. The scFv fragments from an anti-TG antibody are fused to the C terminus of an anti-TPO IgG light (L) chains, or vice versa. It is a type of appended IgGs, which is bispecific and tetravalent (2+2 antigen-binding valency). 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.