In order to accurately analyze the distribution network imbalance caused by distributed photovoltaic access, an optimized configuration based on distributed photovoltaic access distribution network is given for the three-phase unbalance of distribution network. It selects three objective functions (photovoltaic capacity ratio, system network loss, voltage stability margin), and establishes a distributed PV multi-objective optimization configuration model considering three-phase unbalance. In order to solve the problem that the particles do not dominate each other, the multi-objective particle swarm optimization algorithm with minimum angle is used to solve the problem. The validity of the model and method is verified by an example, the results show that the three-phase unbalance of the power distribution system is effectively improved. The research work provides reference for the development of distributed power access distribution network in China. This work is supported by National Natural Science Foundation of China (No. 51877126) and Science and Technology Project of State Grid Shandong Electric Power Company (No. 2018A-073).