Abstract: The stress corrosion crack of small diameter steel pipe girth welds has been an engineering puzzle for a long time.This paper presents a new method for relieving stresses-deformation method by temperature difference.By using general-purpose nonlinear finite element analysis software MSC.Marc,finite element modeling of original residual stress distributions in small diameter steel pipe girth welds and the relief of residual stresses by temperature difference are discussed in this.A serial of numerical analysis data and related rules about heating position,heating band width and heating time,are showed here.It shows that,by using this new method,residual stresses are decreased nearly to zero both on the inner surface and the outer surface of weld.