The welding method of double-sided submerged arc welded spiral steel pipe is submerged arc welding; the forming process is forward swing intermittent production; the unit speed is 0.5-3m/min; the welding speed is 0.5-3m/min. The installation includes de-coilers, straighteners and centering equipment, hydraulic shears, milling and welding machines, disc shears, milling machines, surface cleaning equipment, conveyors, edge pre-bending equipment, forming machines, internal welding, external welding, spraying Sand, pulling out, slag removal, repair welding, flat head chamfering, hydraulic inspection, product inspection, oil removal, and collection.