Aiming at the problem of predicting the residual lifetime after maintenance without considering the multi-stage variability of degradation and the degradation data before maintenance, a method of the prediction of the residual lifetime based on the normal population mean and variation coefficient consistency test of Wiener process is proposed. Firstly, a multi-stage degradation model is established according to the Wiener process. Secondly, according to the degradation monitoring data before and after maintenance, the consistency test of the normal population mean is proposed. Then on the basis of the test results,the H statistic is constructed according to the reciprocal of the variation coefficient,and a method for the consistency test based on probability distribution is proposed. Finally, based on the consistency test results of the degradation data before and after maintenance, the value of the prediction of the residual life is obtained by integrating the data before and after maintenance. The validity of the proposed test method is confirmed by the comparison of prediction errors.