Abstract: Most of the measurement of carbon dioxide in the electric power industry adopts the traditional static emission factor measurement method from the power supply side, while more and more research is carried out in the user side with the proposal of carbon flow theory. To address this issue, firstly, through the carbon flow tracking model, the carbon flow and carbon potential of each node were calculated, the principle of establishing the dynamic factor on the user side was formulated, and the dynamic carbon emission factor model on the substation side was established. Secondly, the definition of the dynamic carbon emission factor on the user side was given based on the spatial variability of the node's carbon potential. Finally, an empirical validation was carried out with a substation area in Shanxi Province under the guidance of a low-carbon demand response mechanism. The correctness of the proposed method was verified by comparing the differences in carbon reduction and carbon reduction benefits under static and dynamic carbon emission factors.