Abstract: Influences of main process parameters on arc anode current density distribution of coupling arc AA-TIG welding were analyzed,using the tungsten probe measurement based on stainless steel anode. Compared with normal TIG arc,the anode current density of coupling AA-TIG arc is obviously lower in the same condition. It is decreased with the increase of arc current and oxygen flowrate in the assisted arc,the decrease of tungsten electrode spacing and arc length. When the spacing between the main electrode and assisted electrode is small,the distribution of arc anode current density fits a Gaussian profile. When the electrode spacing is large,it gradually turns to a bimodal distribution. The anode current density at the arc edge is consistent with a quadratic Gaussian distribution,while that at the middle region between the main arc and assisted arc deviates from the quadratic Gaussian distribution.