Coal-fired power generation causes various resource and environmental problems. In order to alleviate the growing environmental problems, it is necessary for coal-fired power plants to carry out environmental cost management. This paper takes a coal-fired power plant in China as a research object to try to quantitatively evaluate various environmental costs of the power plant from a comprehensive perspective. First, the life cycle assessment (LCA) method was used to analyze the environmental impact of the operation of coal-fired power plants, thereby monetizing the external environmental costs of coal-fired power plants. Secondly, the environmental cost information embedded in coal-fired power plants in other general cost databases is classified to enable managers to obtain comprehensive environmental cost information. The results show that the environmental cost of coal-fired power plants is 24.81 yuan/GJ, of which the external environmental cost accounts for 55.93%, the environmental prevention cost accounts for 41.8%, and the environmental cost during the coal transportation stage is 4.9 yuan/GJ. Through quantitative analysis of environmental costs of thermal power generation enterprises, it can be seen that the environmental costs of coal-fired power plants during the transportation phase cannot be ignored, and should be included in the environmental cost accounting to avoid underestimating environmental costs. The results of this study can be used as a basis for internalizing environmental costs and for companies to carry out environmental cost management to encourage cleaner production and promote the sustainable development of thermal power generation companies.