In this study, taking a certain iron ore tailings pond as the research object, a closed pond engineering design was conducted to ensure its sustained and stable operation. Firstly, installation of a flood drainage system (spillway) and closure of the existing overflow tower and drainage pipe are suggested. Secondly, numerical analysis is conducted on the seepage field of the dam body to determine the position of the saturation line of the dam body under normal water storage level and design flood level. Subsequently, the stability of the dam body under various working conditions is assessed using the limit equilibrium method.