To research the effect of building a sediment interception and drainage system on reducing sediment accumulation in the lower reservoir of Hunyuan Pumped Storage Power Station, a physical model of the lower reservoir of Hunyuan Pumped Storage Power Station was established. In response to the lack of measured hydrological data, after multiple analogies and analyses, the water sediment relationship of the nearby Jiazhuang hydrological station in the watershed was adopted as the inlet water sediment relationship of the model. The experiment set up two operating conditions, one with a dam and the other without a dam. The experiment set up two working conditions, with and without dams, and conducted experimental research on 5 types of non-standard frequency floods, including 30 years, 40 years, 50 years, 80 years, and 100 years. The results showed that during each non-standard frequency flood process, the sediment concentration and suspended sediment particle size distribution along the way in the reservoir area with dam, as well as the sediment concentration and sediment particle size through the machine, were much smaller than those without dam; After exceeding the standard frequency of floods, the sedimentation thickness, sedimentation amount, dead storage capacity, and effective storage capacity loss of the lower reservoir are also smaller than those without dam. The sand prevention effect of this sand retention and drainage system is very obvious. Therefore, it is necessary to build a sand retention and drainage system for the Hunyuan pumped storage power station.