Abstract: In order to improve welding accuracy,welding quality and welding efficiency,an automatic PLC control system for welding wiggler with good interaction interface is designed. Firstly,the mechanical structure of the welding wiggler was analyzed,and a set of welding torch swing control system was designed,which takes OMRON CP1 H PLC as the control core,the touch screen of WLP was the human-computer interaction system,the servo motor was driven by the Panasonic servo motor,and the hardware structure of the control system was given in detail.Based on the hardware structure,the control system software was developed. The experimental results show that the system has friendly display interface,reliable performance and strong stability,and can meet the needs of welding torch swing during the welding process.