Abstract: The debris flow as a common geological hazard has become one of the most harm geological hazards to human. At present people's understanding degree to the research on debris flow is relatively weaker than the study about collapse, landslide and flood. This paper takes a mine debris flow as an example based on solid sedimentary analysis, predicting the flowing characteristics of rainstorm debris flow of large dump, studying the dilute resistance and solid sedimentary law of the low viscosity debris flow. We have used the solid deposition analysis method to calculate the weight of debris flow, velocity, solid flow and total flow rate. Analysis on the process of the debris flow which evolved into a torrent due to some unfavorable factors attenuation such as channel has gotten slowly. The research results have important and practical guiding effect about prediction and prevention of debris flow.