Abstract: Whether the heat pump evaporation salt making process is economical mainly depends on the energy consumption.So how to decrease the energy consumption becomes the key direction of technology improvement.The energy consumption of multi-effect evaporation salt making process can be decreased by changing the structure of the process，increasing the number of the effects，adding preheating equipments，flash evaporation in every effect and so on.The energy consumption of heat pump evaporation salt making process can be decreased by changing the evaporation pressure.By using process simulation software Aspen Plus，the modeling of multi-effect evaporation in vacuum salt process was built to study the measures of decrea- sing energy consumption.In the simulation，at atmospheric and positive pressure（132.5 kPa），25% pure salt solution was used and the energy consumptions at different pressures were compared.Meanwhile it was also compared with the five effects evaporation process. Based on the simulation results，the best process can be chosen and the economic benefits can be maximized.

Key words: thermo-compression evaporation, Aspen Plus, vacuum salt process