Abstract: Targeting at the problems of long-distance heat transportation，low heat grade and high recovery cost existing in waste heat utilization of power plants，a large-temperature difference long-distance heat-supply mode characterized by low return water temperature was proposed. The mode has greatly improved the transmission capacity of the heat-supply network and significantly reduced the cost of waste heat recovery. It made the large-scale waste heat utilization of power plants economic and feasible as well. Considering the potential heating area of cities and towns in northern China which will reach 20 billion square meters，a clean heat-supply scheme was made based on the long-distance heating mode utilizing waste heat from power plants. Compared with the reference scheme replacing coal with gas or electricity，this scheme can save 50% energy consumption，reduce 80% air pollution emission，reduce carbon emission by 200 million tons，and save the comprehensive heating cost by 25%. Since the long-distance heat-supply mode is of large investment and complex relationships with multiple parties，waste heat from power plants should be further stated as the dominant heating source for the clean heating in northern cities and towns in China，and corresponding policies and measures should be carried out to encourage the development of this clean and efficient heating mode.

Key words: waste heat from power plants, low return water temperature, long-distance heat-supply mode with large temperature difference, main heat source, clean and efficient heating mode