Abstract: Taking Dajianshan Lead-zinc Mine 3# tailing ponds in Lianping County, Guangdong Province as examples, this paper carries out a detailed study on the flood drainage facilities before the tailing ponds are written off, and accurately calculated the rainstorm amount. The safety factors affecting the flood control stability of Dajianshan 3# tailings DAMS are deeply analyzed, and it is found that the design flood calculation method is different according to the hydrological data, which mainly includes two ways to calculate the design flood by using the flow data and the rainfall data. By obtaining the physical and mechanical parameters of soil layer, the stability calculation model is constructed and solved, and the safety coefficient and stability coefficient are deeply analyzed. The results show that under normal water level and flood level conditions, the stability safety factor of the dam body of the current tailings pool meets the requirements of the code, and the dam body is in a stable state. The tailings ponds of Dajianshan lead-zinc mine in Lianping County are judged to be normal. However, in order to meet the safety standards of the warehouse, it is still necessary to implement relevant measures such as strengthening the interception and drainage.