Abstract: In order to explore the cause and prevention model of typical river-blocking debris flow disaster, the authors took Qingjia gully debris flow, a typical river-blocking debris flow in the middle and upper reaches of Fu river basin as a study case, and adopted the investigation, field measurement, and comprehensive analysis methods. Four main disaster-causing modes of typical river-blocking debris flow were summarized, including upstream inundation and secondary disaster, downstream flooding and secondary disaster, cross-shore erosion and inundation of the main river, and progressive retreat and siltation in the debris flow channel mouth. Two prevention and control models were proposed based on the fundamental characteristics and disaster-causing mechanisms of this type of debris flow. The first model is sediment interception and source stabilization in the middle and upper reaches, and original channel diversion at the mouth of the gully. The second model is deposition area channel relocation and control. The results show that both models have high feasibility at the technical level of disaster prevention. This study could offer new perspectives and methods for the prevention and control of river-blocking debris flow disasters, and has significant reference value for the prevention and control of debris flow disasters with similar characteristics.