To address the issues of three-phase imbalance and excessive line loss in distributed photovoltaic high-penetration areas, a low-voltage distribution network operation optimization scheme based on the new flexible interconnection device energy storage based phase-changing soft open point (EPC-SOP) is proposed. Under the constraint conditions that ensure the safe operation of the distribution network, a flexible interconnection area operation optimization strategy aiming to minimize the three-phase imbalance and line loss is established based on the EPC-SOP operation model and its constraint conditions. At the same time, the initial model is convexified to reduce the difficulty of solving the model, and the CPLEX solver is used to optimize the solution. Finally, the effectiveness of the proposed optimization strategy is comprehensively verified through specific calculation examples.