The invention discloses a second-class absorption heat pump. The second-class absorption heat pump comprises a generator, a condenser, a high-temperature absorber, a high-temperature evaporator, a low-temperature absorber and a low-temperature evaporator. Part of media inside heat exchanging tubes of the low-temperature absorber are conveyed to the high-temperature evaporator through a pipeline after heat exchanging is performed between the media and solution, and used for making steam needed by the high-temperature absorber in a second-class temperature rising system. The other part of media are conveyed to the exterior of the unit and used for making or directly serving as external heat sources. The heat pump can make a low-grade heat source and a high-grade heat source at the same time, namely, the heat pump, a single-stage second-class heat pump and a second-stage second-class heat pump are integrated, the occupied area of the heat pump is small, the installing space of the heat pump is greatly saved, in this way, the second-class absorption heat pump is easily applied to an environment where installing is limited, and the application range of the second-class heat pump unit is enlarged. Meanwhile, a user can perform single-stage and second-stage selection according to technology requirements and working conditions, in this way, the heat pump operates under the optimal working condition, and the optimal energy-saving effect is achieved.