The invention relates to a method for welding roller with large diameter, and a relative device, wherein it uses special automatic welding rotation table, automatically welding operator and silicon arc controllable rectifier; using oxygen-gas to heat, and using amianthine plate to insulate heat, to preheat the large-diameter roller, and insulate heat interlayer, then cooling slowly, to eliminate stress anneal. The invention can use present device, to weld the large-diameter roller with low cost, while the strength of welding seam can reach 100N/mm2 as torque. |