In this paper, the electrically assisted pressure solid-phase welding of titanium alloy plate is studied. Two different sizes of dies are used to apply pressure to the specimens. At the same time, electric current is applied to the specimens which are in plastic compression deformation. After welding, the joint strength is evaluated by tensile tests. The results show that for the small dies, the optimal thickness reduction corresponding to the maximum fracture load for a given current intensity exists. And the fracture mode changes from shear failure mode to fracture failure mode. While for bigdies, the fracture failure load is greatly increased for the increase of welding area, and the fracture mode is only fracture failure mode.