The butt fusion machine can realize spot welding, butt welding, stitch welding, sealing welding, etc., with high aspect ratio, small weld width, small heat-affected zone, small deformation, fast welding speed, flat and beautiful welds, and no need for treatment or after welding. It only needs simple processing, high welding seam quality, no air holes, precise control, small focus spot, high positioning accuracy, and easy to realize automation.