Abstract: With the integration of a large number of distributed power sources into the distribution network, the risk of bidirectional power flow and voltage exceeding limits in the distribution network is greatly increased. The difficulty of real-time state perception in the distribution network is increased. Considering the high cost of configuring synchronous phasor measurement unit（PMU） due to the large number of nodes in the distribution network, a PMU optimization configuration method considering observable weak nodes is proposed. Firstly, a comprehensive sensitivity index is proposed to measure the degree of node voltage weakness in response to the voltage disturbance characteristics caused by the integration of a large number of distributed power sources. Secondly, based on the principle of economy, while ensuring the optimal global state estimation accuracy of the distribution network, a multi-objective optimization configuration model for PMU is established, which takes into account the comprehensive sensitivity of node voltage, state estimation error, and configuration cost. The improved multi-objective grey wolf algorithm is used to solve the configuration model and obtain the Parato non inferior solution set for the optimal configuration of PMU. Finally, the effectiveness and superiority of the proposed model are verified through simulation analysis using IEEE 33 node and 69 node examples.