The optimal selection of uranium tailings sand cover materials is of great significance to the management of tailings sand in uranium mines. By constructing a radon concentration distribution model for uranium tailings sand cover layer, using single-layer and three-layer cover materials, constructing a multi-objective decision model with radon emanation rate and comprehensive cost as decision objectives, and finding the optimal solution of feasible solutions based on multi-objective non-dominated ranking method. For uranium tailing sand, if single-layer covering material is used, only three materials, namely clay, cement mortar and asphalt, can meet the national standard limit value of radon emanation rate within a reasonable thickness range; compared with single-layer covering material, the radon emanation rate outside the three-layer covering material meets the national standard limit value requirement and the comprehensive cost is reduced by 75.9%.