On the basis of knowing the engineering geologic conditions and geologic structures through investigation, the influence factors on the slope stability were analyzed and, with the geomechanics method, the west-slope integral stability at the mine is also evaluated.The authors consider that the rock fault depression, formed by the graben fault block, and the black fracture zone, formed from the structure action of the Cambrian system formation, are characterized by weakness and easy deformation, which are the important factors to influence the slope stability.Thus, this study has provided strong assurance for the determination of final pit slope angle, slope protection and safety production.