Annular welding device used for pressure vessel

An annular welding device used for a pressure vessel comprises an annular walking rail, walking wheels matched with the annular walking rail and a mounting frame arranged on the walking wheels. A driving device, an electric welding gun, a welding wire coil and a control box are arranged above the mounting frame. The driving device drives the walking wheels to rotate, the gun head of the electric welding gun is vertically downward, and the tail of the electric welding gun is matched with the welding wire coil. The welding wire coil is matched with the walking wheels and driven by the walking wheels to rotate, both the driving device and the electric welding gun are connected with and controlled by the control box, and the control box is connected with a power plug through a guide line. Theannular welding device overcomes the shortcomings of existing technology, first two circular rings to be welded are aligned, then the annular walking rail is installed at a port position, the gun headof the electric welding g