Of these, by a single electrode into a single multi-electrode welding torch welding torch welding method more than the 20th century, Germany's first of 70 multi-seam welding torch along the direction of straight line, forming a long-shaped heat distribution, significantly improve the welding speed; have adopted three-electrode arc welding torch, welding steel thickness of the stainless steel pipe 2mm, single-torch welding speed increased more than 3 to 4 times, welding quality has been improved. TIG and plasma welding used in combination with a greater wall thickness can be welded steel pipe. In addition, the use of 5% argon 10% hydrogen, then using high-frequency pulse welding power source, can also increase the welding speed. Multi-arc welding torch for welding of austenitic and ferritic stainless steel tube.