Abstract: Vacuum diffusion bounding technique was adopted to weld TA22 titanium alloy, the effects of welding temperature on microstructure and mechanical properties of the joints were investigated, and post-weld heat treatment was adopted to improve the comprehensive performance of the joints. The results showed that with the increasing of welding temperature, the tensile strength and yield strength of the TA22 joint decreased, the elongation and reduction of area increased at first and then decreased, and the maximum elongation and reduction of area of diffusion welded were at 950℃. The plasticity of the TA22 joints were improved by annealing treatment.