This paper analyzes the dynamic characteristics of debris flows in Danbobei gully. It summarizes the formation conditions of the debris flows. It confirms that the debris flows in Danbobei gully are gully rainfall type with low-frequency and high viscous debris flows. It analyzes the debris flow characteristics of the movement such as the flow velocity, the discharge, punching power and the transporting quantity. According to the characteristics of development activity of the debris flows and their formation reasons, it is also suggested that building barricade wall at the left bank of the early construction site and the upper reaches materials site. The wall should occupy fewer flood channel cross sections for preventing blocking the river.