Abstract: As it can well solve the data volatility, Wiener degradation model is becoming a popular model for degradation data treatment. However, Wiener degradation model with drifting is aimed at linear degenerate, and even it demands product in same batch with fixed degenerate drift parameter, which limits the range of its application. In this study, Wiener model is adapted to non-linear problems, so that it could be used in more target of evaluation. Shift parameter of the model is supposed a variable changing with evaluation target, which is supplement and perfection for Wiener degradation model. At last, reliability of this model is analysed, basing on the data of pipe crack in nuclear reactor primary loop, to prove the rationality of the model.