The invention provides a composite second absorption heat pump, belonging to the heat pump technology field, mainly comprising a plurality of generators, a high-temperature absorber, a low-temperatureabsorber, an absorption-evaporator, an evaporator, a condenser, a reducer, a regulating valve, a solution pump and a cold agent pump. The steam of cold agent generated by the generator goes into thecondenser, and then cold agent pump provides the cold agent to the evaporator and the absorption-evaporator, and then the cold agent which is throttled and flows into the evaporator absorbs heat and is gasified and then flows into the low-temperature absorber, the absorption-evaporator, and then the cold agent in the absorption-evaporator absorbs heat and is gasified and flows into the high-temperature absorber; thin solution absorbs heat and releases steam with gradually increased consistency, and the steam of the cold agent which flows into the low-temperature absorber and the high-temperature absorber releases heat thereby supply heat for outside. The solution respectively flows through the high temperature absorber, the absorption-evaporator for gradually absorbing the cold agent steam, and flows through the low-temperature absorber for absorbing the cold agent steam, so that the consistency of the steam is reduced and the solution flows into a first-level generator; an intermediate heat-exchanger conducts heat between the absorption-evaporator for heating the solution.