Abstract: A type work-piece has some features such as thin wall, dense space curve welded joint, easy to deform when heated, a high demand of gap and unfitness and so on.According to the structure characteristic and the states of heating and stress for the welding parts, the distortion mechanism of the work-piece has been further investigated and subsection linear control strategy for current to suppresses the distortion has been proposed.Based on the relationship between the gap and the welding current, the subsectioo linear control strategy for the current has been implemented by using the signals of virtual ARC_ON/OFF companied by the current-control signals produced by PLC.It has been approved that the control strategy can be successfully applied in the actual welding production and improves the quality and productivity of the work-piece.