The invention relates to a low temperature high-efficient energy-saving evaporation process, comprising the following process steps successively: heat pump compression, condensing evaporation, water jet condensation and evaporative cooling. The evaporation process utilizes low heat energy which is compressed and improved by a heat pump as a heat source for decompression vacuum evaporation; the heat energy is improved by 5 times. Simultaneously, the cooling capacity of the heat pump is used for lowering the temperature of cooling water of a water jet condenser, improving the vacuum degree of the vacuum evaporation, increasing the evaporation strength, improving the evaporation efficiency and reducing the used amount of the cooling water. Meanwhile, matching equipment investment of a heating system is reduced, and the investment is saved by one fourth. Therefore, the low temperature high-efficient energy-saving evaporation process can achieve the advanced techniques of energy saving and high efficiency, low cost, little investment, pollution-free, and the like. The process is applied to salt industry, sugar industry, seawater desalination, chemical and food industries, etc.