Abstract: Based on the study of slope stability in a domestic open-pit coal mine, the mine has experienced many local landslides and patches since 2015. In this paper, geological survey of slope, engineering geological drilling and other methods are used to analyze the engineering geological and hydrogeological conditions of the southern end slope, and to find out the spatial distribution of rock and soil, the distribution of weak layers and the parameters of landslides. Through field test and indoor geophysical and mechanical properties test, the physical and mechanical properties of the southern end of the rock are obtained, and the landslide back analysis method is used to determine the slope stability evaluation index. Through the establishment of engineering geological model, the limit equilibrium method is used to analyze the stability of the southern end slope, and the comprehensive treatment measures for slope deformation and failure are proposed.