Welding device for upper guide cylinder assembly of nuclear power reactor internals and using method of welding device

The welding device comprises a base, a rotating device, a plurality of supporting seats and a moving seat are arranged on the base, the rotating end of the rotating device is connected with the end of a guide cylinder through a connecting flange, a plurality of guide plates are arranged on the guide cylinder, and the moving seat is connected with the rotating end of the rotating device. The guide plate is connected with the guide cylinder through a plurality of positioning pins arranged on the guide plate, a positioning structure is arranged on the guide cylinder, the positioning structure is matched with a supporting structure arranged on the supporting seat, the movable seat is matched with the base, a manipulator structure is arranged on the movable seat, and a welding head is arranged at the working end of the manipulator structure. By the adoption of the structure, the skill requirement and the operation intensity of welders can be effectively lowered, the production and manufacturing efficiency and the