Abstract: The failure of steep overdip stratified slope is generally caused by slidingbending in unstable cutting slopes of highway in limestone mountainous area. Based on the case study, the geomechanical mechanism and process of the deformation and failure for this kind of slope are illustrated,and discrete element method is used in modeling the excavation effect and final stability of the slope. According to the failure mechanism, a typical reinforcement remedial design of the slope is proposed.