Abstract: As a defect occurring in the manufacturing process, the "spade" defect of shaping weld seam of the spiral weld pipe affects not only the welding quality of the shaping seam, but also the apparent quality of the pipe. Such defect has been a hard problem for the pipe manufacturers to solve and prevent. The elements as res- ponsible for occurrence of the said "spade" defect are analyzed, and accordingly control measures are proposed in order to improve the shaping weld seam quality of the spiral weld pipe, and guide the actual operation more effectively.