Abstract: With the substantial increase in the penetration rate of renewable energy and flexible loads, the random fluctuation of power system operation has increased, and the power grid operation form and system characteristics have changed greatly. Aiming at overcoming the shortcomings of the traditional reactive power partitioning method in matching the dual characteristics variation on both source and load sides, a robust reactive power partitioning method for the frequent power flow fluctuation in the new power system is proposed. By taking into account the physical characteristics of the power system, the topology characteristics of the power grid are used to increase the robustness of the network partition. First, a parameter called“hybrid edge weight”is proposed to define the edge weight of reactive power network topology to provide a scale for the grid structure partition. Then, a power grid partitioning process based on the parallel GN algorithm is designed, and a new partitioning connectivity judgment strategy based on the reachable matrix is introduced. Finally, the IEEE standard system is used as an example to analyze the characteristics of hybrid edge weight parameters, and an actual power grid in a certain area of Eastern China is used as an example to verify. The results show that the designed reactive power partitioning strategy can obtain the high-quality partitioning results in a biased manner, and can effectively stabilize the partitioning boundary nodes under the frequent power flow fluctuation.