Abstract: Taking the currently-used external control type forming process and the ring-cutting process for residual stress measurement as examples, the method for studying residual stress of the high grade helical welded pipe(Φ1 219 mm×18.4 mm, St.X80) is elaborated. And the causes for residual stress developing during the manufacturing process of the said pipe are analyzed theoretically. Moreover some measures for reducing and controlling residual stress of the pipe are summarized via long-time production practices. Such measures are proven to be effective via actual operations, having enabled remarkably improvement of steel tube quality.