Abstract: The electrolytic aluminum load is increasing rapidly in the power grids of the western provinces in China, especially in Yunnan. The results of safety and stability analysis in recent years indicate that the current load model adopted by the power grid planning and operation department cannot accurately describe the load characteristics of electrolytic aluminum. The structure of the aluminum electrolytic power supply system, constant current control strategy, and production process principle of electrolytic aluminum were analyzed in detail in this paper. On this basis, a dynamic load model of electrolytic aluminum considering distributed impedance of electrolytic cell series wire and constant current control system was proposed. Based on the measured load characteristic data of PMU, the accuracy of the 30% constant impedance + 30% constant current + 40%constant power static load model, 100% constant current static load model, 95% constant current + 5% motor model, and the dynamic load model of electrolytic aluminum proposed in this paper were compared and analyzed. The results show that the proposed dynamic load model considering distributed impedance of electrolytic cell series wire and constant current control system has the best fitting effect and can describe the dynamic characteristics of electrolytic aluminum load more accurately.