Abstract: There are abundant rainfall and rich provenance in watershed of Jiaobangou in Dechang county, which are vulnerable to mountain torrents and debris flows. This paper assesses the risk of debris flows combined with the actual climate, hydrology, geology resources, population and economy. The hazard and vulnerability of the debris flow are 0.644 and 0.876,which belongs to highly dangerous, very highly vulnerable debris flow gully. The risk degree is 0.564,which is a debris flow ditch of high risk, it is vulnerable to large-scale debris flows. Based on the characteristics and evaluation results of Jiaobangou debris flow, propose comprehensive measures of combining monitoring and early warning with engineering remediation (rataining dam, blaeking net, solid bed dam, etc) to provide a theoretical support for disaster prevention and reduction of debris flows.