The laser is transmitted from the optical fiber wire to the handheld laser welding gun and focused to the welding surface, absorbed by the carrying material, then converted into heat energy for the melting of the material or the welding wire to achieve the welding effect, and a high-quality welding channel is formed through auxiliary inert gas protection, so that the two objects are firmly welded together. (Chiller water flows to the laser and the handheld welding gun to protect important components. )