The invention relates to a 
heat pump type low-temperature evaporating device and method, belonging to the technical fields of 
chemical separation, 
energy conservation and emission reduction. The method is characterized in that a 
solvent is evaporated and condensed in the heating circulation process of a heat-carrying medium, so that the aim that a thermosensitive material liquid is evaporated and concentrated or an 
organic solvent is recovered at the low temperature can be achieved; the 
heat pump type low-temperature evaporating device mainly comprises a material liquid 
evaporator, a gas-liquid separator, a secondary steam condenser, a condensate tank, a heat medium 
storage tank, a heat medium steam compressor, a filter, a material liquid pump, a 
condensate pump, a throttling device and a pipeline valve, wherein a single-effect or multi-effect falling-film 
evaporator is used as the material liquid 
evaporator. The material liquid evaporating temperature is controlled to be within the range of 25-60 DEG C by adjusting the 
system vacuum degree; and the 
system heating capacity is controlled to be matched with the 
evaporation capacity by adjusting the input power of the compressor at the variable frequency. The 
heat pump type low-temperature evaporating device and method have the beneficial effects and advantages that the gas emission is reduced, so that the environment is protected, and the energy is saved; and furthermore, the active ingredients of the material liquid can be maintained by low-temperature 
evaporation, equipment is seldom corroded, and a pipeline is not easily blocked, so that the equipment cost is lowered.