Accurate measurement of carbon emissions is the data support for achieving the "dual carbon" goal. As the first key industry to enter the national carbon trading market, accurate carbon measurement in the power industry is of great significance. At present, the carbon measurement in the power industry adopts a unified carbon emission factor calculation and each link is measured separately. This method has high particle size, poor real-time performance, and cannot reflect the correlation and characteristics of each link in the power system. The addition of regional distributed power generation systems cannot quickly reflect the impact on the overall carbon emission intensity. Therefore, this paper applies the carbon emission flow theory to organically combine various links of power system transmission and distribution, establish a real-time carbon measurement system for the entire process of the power system that takes into account distributed generation, and propose a carbon emission calculation method for each link of the entire process of the power system. This method can improve the real-time measurement of carbon emissions in the power system, improve measurement accuracy, reflect changes in carbon emissions in the power system, and assist in achieving the "dual carbon" goal.