Through the precipitation simulation experiments using MM5V3 with various parameters for the lowlatitude plateau area, the operational system of the MM5 mesoscale numerical prediction model is established based on the SGI O350 minicomputer. Its precipitation prediction has a time resolution of less than 60 minutes and a horizontal resolution of less than 10 km. By integrating the radar, retrieved satellite data, conventional meteorological data, and intensive rainfall observation data with the weighting method, a refined rainfall field was generated. Based on the relation between weather background and Landslide/debrisflow disasters, the refined weatherbased monitoring and warning system of debris flow disasters for Yunnan Province is established with the PPES model, which has a time resolution of 12 hours and a horizontal resolution of 30 km, and can provide the weatherbased graded prediction products of Landslide/debrisflow disasters