Abstract: Soil erosion is one of the most critical factors which causes flash flood disaster, leads to the loss of life and property, and deteriorates the environment. It can increase the damage caused by flash flood disasters to a certain degree. Combining the characteristics of mountain flood disasters and soil erosion can optimize the allocation of resources, reduce the losses and promote the system construction, which all contribute to improve the flash flood disaster prevention. Based on the data of the flash flood disasters prevention project and the national soil and water conservation census, this paper analyzed the characteristics and current situation of flash flood prevention and water-soil conservation, and further explored their relationship. The strategies and suggestions are proposed which can provide theory and technical reference for the water- soil conservation and mountain flood disaster prevention.