Abstract: This paper researches the integrated method of urban debris flow risk assessment.The method involves the debris flow hazard zonation,the urban vulnerability evaluation and the risk assessment.The debris flow hazard zonation on the alluvial fan of the study area is caused by overlaying the distributed flow depth and velocity maps,which are produced through the numerical simulation.The detailed land cover information is derived by using the Quickbird high spatial resolution satellite imagery,and then we evaluate the vulnerability value through the different land-use features.Based on a GIS statistical and analytical tool the urban debris flow risk assessment for the study area is completed.This risk zonation map can be used for the debris flow mitigation by identifying hazard prone areas allowing for the avoidance through zoning or other land use polices,and provide risk information for the residents who live in the debris flow prone areas in order to plan the evacuation and prevention.