In order to reveal the influence of VPPAW on the weld appearance, 5A06 aluminum alloy was welded by variable polarity plasma arc welding process in this paper, s. The weld appearance was measured and analyzed by single factor control comparison test and analyses. There are four parameters: positive and negative current, plasma gas flow, positive and negative current duration and wire feed aped were tested and analyzed for the influence on the weld forming. The experiment results show that: with the increase of welding current, the reinforcement and width of top weld was increased first and then decrease, while the reinforcement of back weld increased dramatically, but the changes of back weld width was not obvious; as the plasma gas flow rate was increased, the fluidity of weld metal increased accordingly, nevertheless, there were some discriminate changes in the width of back weld and the reinforcement; in the case of increasing the duration of the negative current, the reinforcement and width of top weld was increased slightly, however, the reinforcement and width of back weld was decreased; as the wire feed speed increased, the reinforcement of weld increased dramatically and the width of weld increased slightly. The results show the forming can provide basis welding process support for VPPA welding of aluminum alloy.