The positioner is mainly composed of a workbench, a rotary mechanism, a turnover mechanism, a conductive device, a rack and an electric control box. The positioner is a special welding auxiliary equipment, which is suitable for the welding deflection of rotary work to obtain an ideal processing position and welding speed. It can be used with an operator and a welding machine to form automatic welding. It can also be used for the workpiece deflection during manual work. The worktable rotation adopts stepless speed regulation by frequency converter, with high speed regulation accuracy. The remote control box can realize remote operation of the worktable, and can also be connected with the control system of the operator and welding machine to achieve linkage operation. The welding positioner is generally composed of the rotary mechanism and the turnover mechanism of the workbench. The workpiece fixed on the workbench can reach the required welding and assembly angle through the lifting, turnover and rotation of the workbench. The workbench rotation is variable frequency stepless speed regulation, which can obtain satisfactory welding speed.