Abstract: Abstract：The presence of weak basal layers and inclined foundations can induce landslide hazards at end-slope of open-pit mines. Taking the east end-slope of the second mining area in the Zhundong Open-pit Coal Mine as a case study, this research analyzes the geological conditions and structural characteristics of coal-rock layers through field investigations. A three-dimensional numerical model is established to simulate the slope behavior under different scenarios, analyzing the displacement and maximum shear strain incre-ment of the critical unstable slope, and identifying two failure modes. Additionally, the rigid-body limit equilibrium method is applied to calculate the slope stability coefficient under varying coal pillar geometries. Results indicate that slope instability is mainly controlled by overall sliding along the weak basal layer and local failure of the coal pillar. Widening the coal pillar bench significantly enhances local slope stability, with a maximum improvement of 45.2% compared to the pre-optimization state. Expanding the haulage ramp width effectively increases the overall stability of the end-slope, with the safety factor improving by up to 13.9%. Considering both safety and economic factors, the optimal coal pillar width is determined to be 40–80?m, and the end-slope angle is 19–22°, providing high practical engineering value.