Abstract: Based on the morphological characteristics of the debris flow area,this paper chose the Karst area Chuandong Village gully Debris flow basin as a typical example,because ofits unique geographical features in Karst area,the author analyzed that soil erosion provides the necessary source conditions for the process of debris flow.Based on remote sensing image,field investigation and spatial analysis technology of GIS,the author divided the dangerous areas in the study area,and makes the classification and assignment of the selected evaluation indexes,and obtains the vulnerability evaluation results from the two aspects of life and property loss.Finally,the debris flow risk assessment in the study area was completed by superposition analysis.The results show that the middle and high risk areas account for 71% of the total area,and the population is densely populated.The evaluation results are consistent with the actual investigation,which shows that this method can also be applied to the risk assessment of debris flow in Karst area,it also provides an important reference and basis for debris flow prevention and mitigation planning.