With the increase in the proportion of electricity in terminal energy consumption, the accounting of electricity carbon emissions is becoming more crucial for enterprises to save energy and reduce carbon emissions. At present, the calculation of the residual mixed factor（RMF）in China has not been realized at the grid-region and provincial levels, making it difficult to accurately reflect the value of green electricity. A calculation method for provincial RMF considering the deduction of green electricity is proposed. Green electricity is deducted from the inter-provincial transmission and provincial-level power generation in the calculation. At the same time, the calculation method of the provincial average emission factor（AEF）is improved, revealing a linear relationship between RMF and AEF, where the coefficient between the two is equal to the proportion of residual electricity in regional electricity consumption. The verification using the electricity data from 2021 to 2023 shows that this method can effectively reflect the carbon-reducing effect of green electricity on the receiving provinces. In the future, the impacts of grid losses and the deduction of all market-based electricity transactions on the calculation method will be considered to further improve the market-based enterprise electricity carbon emission accounting method.