Abstract: During the operation of the spallation neutron source, heavy water used as a coolant can introduce impurities. Direct purification of heavy water using conventional ion exchange resins can lead to the displacement of H⁺/OH⁻, thereby reducing the purity of heavy water. Therefore, the resin needs to be deuterated. This study focused on Na-form cation exchange resins and utilized the ion exchange method to prepare deuterated resins. The results indicate that the Langmuir isotherm effectively can describe the equilibrium data for the adsorption of D⁺ on Na-form cation exchange resins. Analysis of thermodynamic parameters, including Gibbs free energy(∆G), enthalpy(∆H), and entropy(∆S), reveals that the adsorption process is spontaneous and that the adsorption capacity of the resin increases with increasing temperature. ICP-OES analysis further indicates that a deuteration rate of 98% is achieved when the DCl concentration exceeds 0.8 mol/L. Additionally, the adsorption kinetics of D⁺ on Na-form cation exchange resins at various temperatures aligns well with the pseudo-second-order kinetic model, with adsorption rates increasing as the temperature rises. In fixed-bed experiments, an elevation in bed temperature results in a shortened mass transfer zone, facilitating faster saturation of the resin bed. Consequently, 333 K is identified as an optimal preparation temperature for these materials. The performance of D-form cation exchange resin is not significantly different from that of H-form cation exchange resin. This study can provide some references for the preparation process of deuterated cation exchange resin.