Specially designed for heavy-duty box beam structure of large-scale welding workstation, is the first in the country. The maximum load and turnover weight of the ring and C-type turning mechanism is 60 tons, the actual workpiece diameter is up to 6 meters, the longest is 30 meters, and the two stations have a total rail of 80 meters, forming a complete station with two sets of gantry welding robots. The positioner is portable and can be easily opened or disassembled, and the inner mouth installation card can be easily adjusted to adapt to various sections of the box structure beam. It is suitable for efficient welding of internal and external welds, while considering the outer T-shaped steel, flange plate, horizontal channel steel (or Angle steel). And to ensure that the workpiece to the rolling tooling lifting has enough anti-collision ability.