Abstract: Described in the paper is the issue of forming angle zero drifting of the driving roll as used in the finishing welding process for the SAWH pipe, and the hardware architecture and software design of the correction system as researched and developed for fixing this problem.Also detailed here is the PLC control program which is used for realizing zero correction of the said forming angle.The trial operation of the correction system shows that it features consistent performance, remarkable effectiveness of zero adjustment of the forming angle, and easy operation, being capable of enhancing welding quality and the automation level of the production line.