Affected by the reservoir water and rainfall and other factors, the stability of the landslide changes with the different reservoir water level decline rate. Using the jipazi landslide in Yunyang County, Three Gorges Reservoir as an example, the saturated unsaturated numerical simulation method to calculate the reservoir water level rising and falling of groundwater seepage field, the calculated pore water pressure is used to limit equilibrium analysis of landslide, and discusses the drawdown of reservoir water level on the stability of the landslide. The calculation results show that, as the water level fell from 159m to 145m, and the increase of the reservoir water level decline and phreatic decline amplitude increases. The stability coefficient of landslide is larger than that of the original design, and the decrease rate of reservoir water has a qualitative effect on the stability of the landslide, but the influence is very small.