Abstract: According to the high and steep slope at the northwest side of Antaibao Open-pit Mine, we introduce the engineering background and present situation of landslide. Combined with the engineering geology and hydrological environment data, the mechanism of strong rainfall influence on slope stability is analyzed; and combined with the SLIDE software, slope is divided into 50 strip blocks, then the slope stability in saturated water drainage condition after strong rainfall is simulated and analyzed by the path search method. The results show that the slope stability coefficient in saturated water drainage condition is about 0.841 and the most dangerous sliding surface is located in the upper slope, passing through the upper soil and silty soil. But the slope stability coefficient in the drainage condition is 1.010 and the most dangerous sliding surface is still located in the upper slope, whereas sliding zone is obviously reduced compared to saturated condition and sliding surface is also decreased.