Abstract: D₂O is widely used in nuclear research as a moderator and coolant in nuclear reactors. When using water distillation process to concentrate D₂O, due to the similar properties of deuterium and hydrogen, a larger reflux ratio(50-200) is required, resulting in high energy consumption of the distillation tower. In this study, the characteristics of the mixture separation system of D₂O and H₂O were firstly analyzed, and the distillation process of D₂O concentration was established by ASPEN software. Its operating parameters such as the number of tower plates, feed position, and reflux ratio were optimized. The simulation results show high energy consumption in conventional distillation. The use of heat pump distillation technology can effectively reduce the energy consumption of the distillation system. This paper proposes a new heat pump distillation process for D₂O concentration. By analyzing the principle and applicable scope of heat pump distillation, the operating parameters of the new process were optimized and the operating conditions of the circulating working fluid flow rate of 323.66 kg/h and the compressor compression ratio of 3.3 were determined to meet the separation requirements and reduce energy consumption. By comparing the thermodynamic parameters and energy consumption analysis of conventional distillation and heat pump distillation, the results show that the heat pump distillation has good application prospect in the D₂O concentration process. The comprehensive energy consumption than conventional distillation reduces by 61.28%, energy saving benefit of 66.66%.