District heating systems play a key role in environmental pollution due to unreasonable heating energy structure and low energy efficiency. The shortage supply and expensive cost of natural gas couldn’t meet the increasing demanding of heating load, while the industrial waste heat is dissipated, such as the circulating water in combined heating and power (CHP) plants and the industrial waste of steel plant. Through the comparison of different heating modes, a clean district heating mode is presented to build a safe, stable, clean, economical and efficient heating system. Firstly, industrial waste heat of large-scale coal-fired CHP plants far away from city share the base heating load, which recovered fully by absorption heat pump or compression heat pump to achieve relative clean coal utilization. Secondly, long-distance pipeline network deliver the heat with large temperature difference. Thirdly, distributed clean gas consumed in city share the peaking load. And a new heating system of industrial waste heat recovery based on the Co-generation-based absorption heat-exchange (Co-ah) cycle is presented, which heat supply from energy first station of waste heat recovery in CHP plant to long-distance pipeline network with large temperature difference, to booster energy substations, to primary heating pipe network, then to distribute heat both to existing heat exchange substation and new absorption heat exchange substation, and finally to secondary heating pipe network for heating buildings.