Abstract: A method for planning and designing a debris flow drainage channel is provided. The position and total length of the drainage channel and a longitudinal slope of a gully bed of the drainage channel are determined. An inlet section, an outlet section and an acceleration section of the drainage channel are formed as fully lined channel type. After determining the length of the inlet section and the included angle between the side wall of the inlet section and the main channel, the length of the outlet section and the included angle between the side wall of the outlet section and the main channel, and the length of the acceleration section, the channel type and the length of the main channel section are also determined.