Abstract: Aluminum industry sludge tailings pond has a sludge type dominated by fine-grained silt, and currently disposes surface water through a single pipeline. After the rainfall, the surface water cannot be timely discharged, which affects the solidification of the pond sludge and becomes a natural mudslide risk source. Guangxi Baise tailings pond is selected as the study area, combined with local geographical conditions and waterlogging characteristics. Builded the SWMM model of the pond area, calculated the flood volume in the pond, and carried out the drainage design for the pond area. The results show that the model runoff coefficient after parameter calibration is 0.683, and the Nash-sutcliffe coefficient is 0.833, indicating that the model has high accuracy. The preliminary design of the pipeline is not applicable to the drainage design of the pond area according to the current specifications, resulting in over 85% of the pipelines and nodes being overloaded under different return periods of rainfall, with an overload duration of about 7 hours or more. Targeted overloaded pipe improvements have resulted in significant reductions in overloading rates and duration of overloading for nodes and pipes under different recurrence periods of rainfall. The peak flow on the reservoir surface has decreased by about 58%, the flood peak has been advanced by about 35 minutes, the water volume on the pond area has been reduced by about 30%, and the ponding time has decreased by about 3.5 hours. The drainage capacity of the pond area has significantly improved. Realized the modeling and calculation of the hydrology of the closed pond and mud discharge pond basin, providing a new method for similar engineering hydrological calculations.