This circumference welding machine is a highly efficient, dual-gun, dual-station automatic welding system designed specifically for welding the inner and outer circumferences of long pipes and double flanges. It flexibly accommodates a variety of welding methods, including TIG, double-shielded arc welding, MIG/MAG welding, and plasma welding, to accommodate diverse materials and process requirements. The circumference welding system boasts a high degree of automation, significantly improving welding efficiency and quality, making it ideal for high-volume circumference welding of pipe flanges.