Abstract: Kuaguo Gully debris flow is distributed in Zagunao Valley, a tributary of the Minjiang River, which has caused great losses to residents, provincial road and other infrastructures. Favorable topography conditions, abundant source reserves and short-time strong rainfall process are the conditions for the formation of the debris flow. Through field investigation and laboratory test, the particle composition of the debris flow were analyzed, the scour and deposition characteristics of debris flow were expounded in detail, which were helpful to further understanding the process of debris flow activity. Based on field investigation and theoretical analysis, the kinetic parameters of debris flow, such as flow velocity, flow rate, total amount of one-time debris flow and joint punching pressure of debris flow were calculated. It is determined that the Kuaguo Gully potential debris flow is currently in the development period, and predicted that a larger debris flow may occur under heavy rainfall or strong earthquakes, depositing and destroying the houses on both sides of the gully, and even the G213 State Road.