Plasma welding can be divided into valve cone surface and rod end plasma welding. The equipment adopts PLC and touch screen for program control and data storage, and can store multiple sets of welding parameters. The welding gun is installed on a servo driven module, which is used for relative movement of the welding gun in the Y direction with the process parameters during overlay welding. The X-axis and Z-axis of the welding gun are manually adjusted by a mechanism. The device can be connected to the upper computer for use.