The stepwise regression can apply to deal with the problem of multiple co-linearity between primary factors, and solve the correlation between random variables, and determining the significant variables. Basing on the stepwise regression and combined analyzing measured data regression, the results showed that the fitting effect stepwise regression model is well, multiple correlation coefficient is large, reflecting the different significant influence factor and develop trend, predicting the water level with the regression model can provide guidance for the understanding of the status of the dam seepage.