Abstract: The traditional optimization algorithm is difficult to achieve the balance among multiple objectives when dealing with the optimization of distribution network energy storage system, and it is easy to fall into local optimal. Therefore, a globally searchable multi-objective optimization allocation method for energy storage system of distribution network is proposed in this paper. Firstly, taking node voltage fluctuation, network energy loss and investment operation and maintenance cost of energy storage system as optimization objectives, the optimal configuration model of energy storage system is constructed. Secondly, an improved multi-objective particle swarm optimization algorithm is designed to enhance the global search ability of the algorithm by adaptive inertia weight, and to avoid local optimization effectively by cross-mutation operation. At the same time, fuzzy decision method is introduced to select the optimal solution from Pareto non-inferior solution set. Finally, based on the simulation analysis of IEEE33-node system, the results obtained by the improved multi-objective particle swarm optimization algorithm used in this paper are compared with the traditional algorithm, the node voltage fluctuation is reduced by 10.5%, the cost is saved by 24.6%, and the solution time is shortened by 27.9%. The results show that the proposed method can effectively suppress node voltage fluctuation while reducing investment operation cost and network energy loss, and verify its economy and reliability.