Comparison Study on DC PAW、high-frequency pulse PAW(HF-PAW) and one keyhole per pulse PAW procedure on TC4,the weld joint appearance of the high-frequency pulse PAW and one keyhole per pulse PAW are better than DC PAW,and the mechanical properties and processing properties of the three procedure measure up to the standard. As the High-frequency pulse,the high-frequency pulse PAW reinforce the arc force,bring down the probability of undercut,and raise the travel speed. The weld joint appearance of one keyhole per pulse PAW is smooth and uniform,the front of the weld joint is not subside at all,the mechanical properties test and the SEM test show that one keyhole per pulse PAW procedure is superior than traditional DC PAW,and this procedure is more suitable for TC4 PAW.