Recombinant Anti-FN1 x Anti-HSG Bispecific Antibody (scFv-Fc) is formed by fusing two different scFv fragments to the hinge and Fc regions, in which the Fc region are engineered by KIH. Two of scFv moiety has the antibody variable domain of either anti-FN1 specificity or anti-HSG specificity, which produces bivalent IgG-like molecules with desired characteristics of intact antibodies. This BsAb can be used in pretargeting system of PET, radioimaging or radiotherapy. It can mediate targeting of radioactivity to tumor cells. It is designed for the research of Solid tumors imaging and therapy.