The article took thermal power plant for example, construct five industrial chains: heat and power cogeneration, sea water desalination, salt manufacturing, salt chemical and waste reuse. According to system analysis, the paper studied various factors of thermal circulation economy. It also use systematic function theory and analytic hierarchy process to construct the advantages function of cycle economic, and tries to explore a new comprehensive evaluation method for power plant circular economy. Research shows that desalination recycle economy mode will promote the utilization rate of resources and energy from each aspect for enterprises, it also improve ecological environment of power plant, so as to realize the sustainable development of thermal power plant.