Abstract: Based on the process of heat pump evaporator technology, a method of using heat pump evaporator technology instead of traditional natural (or forced) circulation evaporator technology was proposed in the nuclear power plant radioactive liquid waste processing. According to the results of material balance and heat balance of the heat pump evaporator process, analysis of thermodynamic methods was carried out to clarify the advantages of energy saving of heat pump evaporator technology. The results show that the energy and exergy efficiency can reach 75% and 90% in the specific design conditions, which theoretically proves the advantages of energy saving.