Abstract: Because of the complexity of corrosion environment and stochastic corrosion process of nuclear power pipeline, a prediction model of corrosion pit depth was established based on fractal theory, and the model was used to predict the maximum corrosion pit depth and the probability of depth no more than rd. In order to improve the precision, the nonlinear equation was linearized in the prediction process. The calculated results indicate that using fractal prediction model to predict the corrosion pit depth is feasible, and the prediction results are helpful for analyzing the reliability and security of corrosion pipeline, and mastering the performance of corrosion pipeline.