The invention belongs to the technical field of energy sources, and relates to a concentrated heat supply system for reclaiming smoke afterheat by an absorption heat pump. The system is used for reclaiming smoke afterheat of natural gas and water. The system is composed of a smoke flue, the absorption heat pump, a spray device, a water quality processing device and a circular water pump; smoke flows in the smoke flue from bottom to top; circular water is ejected by the spray device to form atomized drops for directly contacting with the smoke to exchange heat and is introduced to an evaporator of the absorption heat pump by the water pump after being processed by the water quality processing device after flowing out from the smoke flue; hot net returned water is sequentially introduced toan absorber and a condenser of the absorption heat pump; the circular water absorbing heat of the smoke and the hot net returned water are subjected to heat exchange in the absorption heat pump to reach the needed temperature and then are returned to a hot net. The smoke and the water are in direct contact for heat exchange in the invention; the heat of the circular water heated by the smoke is extracted from the absorption heat pump to raise the temperature of the returned water of the heat supply system; thus the total energy utilization rate of the concentrated heat supply system is increased; and the effects of cleaning the smoke and protecting the environment are achieved.