通过水工物理模型试验，对贺江都平河段修建电站前后的水流流态、流速分布和坝下游水面波动进行比较；以及土工试验成果，对岸坡的稳定性和电站蓄泄调度对下游岸坡的影响进行分析，从水力学及土力学方面对都平电站下游河岸崩塌原因进行较为客观的剖析，提出了山区河流上中小型水电站设计与运行时应注意的问题。 Through the hydraulic physical model test, the water flow pattern, the flow velocity distribution and the water surface fluctuation in the downstream of the dam are compared before and after the construction of the Hejiangdupinghe Hydropower Station. And the results of the geotechnical test, the stability of the bank slope, This paper analyzes the causes of the bank collapse downstream of the Du Ping Hydropower Station from the aspects of hydraulics and soil mechanics, and puts forward the problems that should be paid attention to in the design and operation of the small and medium sized hydropower stations in the mountainous rivers.