Shangyao valley is located in Jin'an village of Songpan in Sichuan． Many material sources are accumulated in valleys． The debris flow will be triggered by a rain storm with short-duration and strong intensity， which may threaten people's lives and property in downstream． Based on the investigation，the formation conditions of debris flow and its dynamic characteristics are analyzed and its hazard assessment is investigated． Research shows that there is the potential cause of debris flow in Shangyao valley，which is of the middle risk class．