Heavy-duty 1-ton positioner can weld large workpieces. It adopts AC variable frequency motor, which is easy to operate. The turning is electric, and the motor has a braking function. The working surface plate adopts a double-layer platform or full-page finishing design. It has the characteristics of reasonable structure, good rigidity and long service life. It has a T-shaped groove, which is more convenient for fixing the workpiece. The chuck can be configured according to customer requirements. The rotation angle of the workbench is 0-120, which can be controlled jointly with the operating machine or welding machine to achieve free flipping.