Abstract: The piercing process is studied and relevant tools and dies are improved, addressing the problems as staying with the L80-13Cr stainless steel i.e., poor thermal plasticity, high plug consumption during piercing, easy sticking of steel on the surface of the guide plate, and serious defects of internal and external folds of the pipe, etc. The optimum soaking temperature of the L80-13Cr stainless steel billet is determined to be 1 200 ℃ via the high temperature thermal simulation test. The problems of short rolling span of the plug and surface steel sticking of the guide plate are fixed by means of using the reinforced stainless steel plug and the used high nickel chromium steel guide plate. Furthermore the surface quality of the shell is obviously improved, and the primary qualification rate of the finished pipe as rolled with the shell is increased from under 20% to over 70%, owing to taking such measures as improving piercing process parameters, enlarging the biting angle from 10° to 12°, getting the plug lead screw-down rate limited within the range as 4%~6%, and keeping the ovality coefficient within the range as 1.05~1.10.