During the forming process of submerged arc welded spiral steel pipes for drainage, the deformation of the steel plate is uniform, the residual stress is small, and the surface does not produce scratches. The processed submerged arc welded spiral steel pipe has greater flexibility in the size range of diameter and wall thickness, especially in the production of high grade thick walled pipes. It has advantages that cannot be compared to other grade thick walled pipe processes, and users can have more requirements for the specifications of spiral steel pipes.