Abstract: Taking the C-shaped deformation zone of an open-pit coal mine in Inner Mongolia as the research object, to obtain the slope failure mode and deformation law of the area so as to take targeted prevention and control measures, firstly, the situation of slope deformation and landslide in this area in recent years was understood, and monitoring points were arranged in different positions of this deformation area to form monitoring lines, and GPS monitoring was carried out in the corresponding area. Through the statistical analysis of the deformation data of each monitoring line and monitoring point, the deformation area of the open-pit mine slope is delineated, the failure mode and deformation law of the slope are studied, and the deformation trend of the area is predicted. The rate of slope deformation in this area is related to mining activities and local seasonal climate.