Abstract: This paper applied the unmanned aerial loaded radar technology in slope displacement monitoring of open-pit coal mine to obtain the digital elevation model （DＥＭ） of the open-pit slope through the research on the components of airborne laser radar system and distance measurement principles, as well as the research on data generation and data processing flow. The analysis of the point cloud data show that the DEM and the shape of the slope can be obtained from such technical approach. And this can provide effective early warning for mine slope deformation monitoring and disaster forecasting.