For the displacement machine, the worktable of this model has an overall flipping degree of freedom, which can flip the work to the ideal welding position for welding during operation. Mainly used for welding pipes and plates. Convenient to move, it is currently a commonly used structural form, often used in conjunction with telescopic welding operators. Welding positioner is a displacement machine that combines flipping and rotating functions. Flip and rotation are driven by two shafts respectively. The worktable that holds the workpiece can not only rotate around its own axis, but also tilt or flip around another axis. It can adjust the welding seams at various positions on the workpiece to a certain degree or "ship shaped" easy welding position for welding, suitable for welding frame type, box type, disk type and other non long workpieces.