Abstract: Theoretically analyzed is the residual stress of the SAWH pipe， and accordingly derived is the functional relationship between the residual components ，i.e.，the circumferential stress & the shearing stress，and the axial opening length & the displacement length. Then，the said stress components are combined to get the general stress calculation formula with which the residual stress of the 囟1 016 mm伊17.5 mm L485 SAWH pipe is computed out. The analysis result shows that along with increase of both the opening length and the displacement length，the SAWH pipe’ s residual stress is going up. This residual stress calculation formula features simplicity and easy use.