Metal plate box welding device

The utility model discloses a sheet metal box welding device which comprises a supporting frame, a supporting plate is installed at one end of the top of the supporting frame, a welding head is installed at the bottom end of the supporting plate, and a protection structure is arranged outside the welding head. By arranging the adjusting structure and rotating a rotating handle, the rotating handle can drive a threaded rod to rotate, in the rotating process, a movable block can be driven to move left and right outside the threaded rod, and then the bottom end of a hinge rod can be driven to move in a first reserved groove along with the movable block; through arrangement of a first reserved groove, the top end of a hinge rod can be driven to support one side of the adjusting shell to rotate around the hinged position, then a metal plate box body at the top end of the adjusting shell can be driven to rotate at a certain angle, and through arrangement of a third reserved groove, the adjusting shell cannot be inf