Abstract: Based on the detailed analysis on geological structure and regional geological environment of landslide on the bank of reservoir on the Jinsha River, stratum occurrence, hydrometeorology and other factors, a geological model for Biyouzhao landslide was established by using ANSYS and Flac3D. Then combined with strength reduction method and finite difference program, the displacement and displacement rate of the landslide in the full process from the initial deadweight balance to critical slipping instability under multiple working conditions were calculated and the failure mode and slipping characteristics of the landslide were analyzed, and the slipping plane was determined by the shear strain incremental cloud map. Through numerical simulation, the evolution characteristics and instability mechanism of landslide failure were explained. The results of plastic deformation and displacement analysis showed that the landslide was basically stable in natural state and unstable under the condition of continuous intensive rainfall, which was consistent with the results of field investigation and analysis. Using Flac3D to analyze and evaluate the landslide stability is simple, feasible, and more intuitive and convenient than the conventional method.