Considering the effect of time, rainfall and temperature on slope deformation, we analyzed the deformation factors and their expressions in depth. We also established a statistical regression model of slope deformation through Matlab software and stepwise regression algorithm to carry out regression analysis and prediction of slope deformation. Analysis on the deformation monitoring data of high slope on the left bank of spillway of Dongjin hydropower station showed that the statistical regression values of slope deformation were in good agreement with measured values, with large multiple correlation coefficients and small residual standard deviations. This model can well reflect the slope deformation and its trend, and it provides guidelines for analyzing the safety and predicting the deformation trend.  