Abstract: Through macroscopic examination,several kinds of non-destructive testing,on-site hardness testing and metallurgical coating examination,SA335-P22 steel main steam pipe which had accumulatively run for more than 113 000 h was studied.And combined Larson-Miller formula predicting method and creep damage level taxonomy method,remaining life of the main steam pipe was evaluated.The results show that the remaining life of the pipe was not more than 105 937 h,which could provide a reference for the power plant operator.