Abstract: In order to analyze the influence of different types of rainfall on slope stability of open pit dump, 72 h of different rainfall types were loaded to carry out the seep-sigma-slope coupling analysis. The results show that the negative pore water pressure decreased gradually within 8 h to 14 h of rainfall and became a steady value when the rainwater infiltration is stabilized; the initial rainfall intensity has a great influence on the slope stability, and the lowest safety factor of the slope is 1.422 under rainfall A and the decrease rate was 11.24%; the displacement of the dump slope in x and y directions increased fastly during the early rainfall and then it increased slowly.