Energy combustion is the primary source of CO2 emissions in China. Coal-fired power generation, in particular, is a significant consumer of energy. To achieve the carbon peaking and carbon neutrality goals, it is crucial for coal-fired power plants to select suitable methods for calculating CO2 emissions and accounting for them. Starting from the carbon emission sources of coal-fired power plants and using the principle of least squares, qualitative and quantitative analyses, different methods for calculating CO2 emissions from coal-fired power plants are analyzed. A comparative analysis model is established to compare the calculation results, data acquisition costs, carbon trading cost, and comprehensive accounting costs of different CO2 emission accounting methods. The computational results illustrate that the CO2 emissions derived from the material balance method closely approximate the measurements obtained through continuous monitoring techniques, with the data acquisition costs and carbon trading costs stemming from carbon emission characteristic coefficient calculations being minimal.