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.