Welding automation is mainly used to improve welding efficiency. When some cylindrical workpieces need to be rotated, the welding rotator can help rotate the workpieces to facilitate welding. When some workpieces are irregular in shape and heavy in weight, the welding positioner can fix the workpiece on the table, rotate, tilt, lift, etc. to achieve the ideal welding position. If manual welding is difficult, the welding manipulator can be used to automate the welding process to weld cylindrical workpieces such as pressure vessels, wind towers, sea piles, etc. more efficiently.