The anti-ad fiber knob x anti-ITGAV bispecific antibody is intended to be fused to the N-terminus of the Knob-CH3 domain and the anti-ITGAV scFv to the Hole-CH3 domain, or vice versa, in the recombinant Anti-Ad fiber knob x Anti-ITGAV Bispecific Antibody (Minibody). C-terminal disulfide linkages additionally stabilize the CH3 domains. Adenoviral vectors can be retargeted by this BsAb to tumor cells. It can be applied in cancer gene therapy to deliver a therapeutic gene to tumor cells with the goal of efficient and targeted cell death.