Abstract: A kind of coupling arc tungsten electrode was developed to decrease arc pressure remarkably,avoid undercut and humping weld.Adopting this method, high-quality TIG welding with relative higher speed can be achieved.The TIG arc pressure of this kind of welding process was tested to investigate the influence of the parameters on distribution of arc pressure.Compared with the traditional TIG arc,the TIG arc pressure with coupling arc electrode is much lower with the same parameters, and decreases with the increase of arc length,the increase of electrode extended length,the decrease of current,the increase of the electrode gap width and the increase of the electrode diameters.The arrangement of the influence in decreasing order is current, electrode extended length,arc length and electrode diameter, electrode gap width.