摘要:In this paper, we have systematically studied the impact of different Fredlung & Xing unsaturated parameters on the permeability and stability of the landslide with a sudden drop in reservoir water level. Taking a landslide of a reservoir area in Yunnan province of China as an example, the slope/w mod-ule and seep/w in the geo-slope software ofgeotech-nical engineering are used to study the pore water of different monitoring points of the landslide and the law of pressure changes and landslide stability at dif-ferent reservoir water levels under different unsatu-rated parameters. The calculation results show that when the water level of the reservoir continues to drop,the pore pressure of monitoring points at dif-ferent elevations will decrease, and the safety factor of the landslide will generally decrease first and then increase. When the reservoir water level drops sud-denly when the value of a is small, and the value of m and n is large, the minimum safety and stability factor of the landslide is relatively small. The greater the rate of sudden drop of the reservoir water level and the smaller the minimum safety factor, shallow landslides often occur before deep landslides. The bank slope landslide caused by the sudden drop of the reservoir water level will cause the reservoir wa-ter level to rise sharply, and cause the reservoir water to overflow, and ultimately cause huge damageto the surrounding environment.