Abstract: The hydrated manganese dioxide (HMO) was prepared by the oxidation reduction method with potassium permanganate as starting materials, while the resulted HMO was characterized by XRD, BET, TG-DTA and FT-IR. In the adsorption experiment, the influences of various experimental conditions were investigated, and HMO was also applied for the actual treatment of ⁶⁰Co wastewater. Experimental results show a good adsorption property of Co²⁺ on HMO, in the condition of pH=7 and T=298 K, with a maximum adsorption capacity of 132.98 mg/g. The pH of the solution can significantly affect Co²⁺ adsorbed on HMO, and in the experimental pH range, the adsorption capacity increases with pH. Under the same Co²⁺ initial concentration, the adsorption capacity increases with temperature. Co²⁺ adsorption on HMO is influenced while Na⁺, K⁺, Mg²⁺, Ca²⁺, Zn²⁺ and Fe³⁺ coexisted in the solution. The adsorption behavior of Co²⁺ on HMO is well described by pseudo second order kinetic model and Langmuir isotherm model (R²＞0.99), and it is indicated that the adsorption process maybe a chemical and monolayer adsorption. The adsorption thermodynamics data of ΔH=46.96 kJ/mol and ΔG=-26.09 kJ/mol show that the adsorption process is endothermic and spontaneous. In addition, when treating wastewater containing ⁶⁰Co whose initial radioactivity concentration is 2.78×10⁵ Bq/L in the dynamic column experiment, the removal rate is 56.90%.