By comparing the remote sensing images before and after the debris flow and taking ArcGIS as an analyzing tool, it is found that "8.8" extremely big debris flow carries large amount of solids with a total volume of 1.521 8 million m3, damaging buildings and blocking rivers. It forms 1.9 km long narrow deposits with a volume of 1.105 8 million m3 and the maximum accumulation thickness of 10.8 m. For accumulation characteristics of debris flows are the objective records of the beginning and developing process of debris flows, this paper analyzes accumulation characteristics and destruction degrees in different parts of earlier debris flows and "8.8" debris flow. The results can be taken as references for comprehensive treatment and post-disaster reconstruction planning.