Abstract: TA1/Q345 composite plate welded structure has a wide application prospect. The steel wire, copper wire, vanadium wire and titanium wire were used in turn for gas shielded arc welding of the composite plate. The microstructure and composition of each zone of the composite plate welded joint were analyzed by metallographic microscope, scanning electron microscope and energy dispersive spectroscopy. The results show that the weld joints has good appearance and is free of cracks, incomplete penetration, undercut and other defects. The weld zone of the welded joint is divided to Fe zone, Cu zone, V zone and Ti zone, and the boundaries of each zone of the weld are obvious. Near the Cu-V interface, spherical vanadium-based solid solution particles are distributed at the copper matrix, which significantly improves the bonding performance of the interface. The vanadium isolation layer and copper isolation layer can effectively prevent the diffusion of Fe and Ti elements, which inhibits the formation of brittle intermetallic compounds. The hardness of each zone of the weld is stable. The elongation of the welded joint is 17%. The tensile strength of the welded joint is 517 MPa, which is 94% of the tensile strength of Q345 base metal.