Abstract: Under the background of high proportion distributed resource access, in order to fully explore the loss reduction potential of reactive power regulation of the distribution network and reach the target of loss reduction through reactive power optimization technology more comprehensively and precisely, this paper proposes a multi-objective reactive power optimization and loss reduction method considering the coordination and interaction of multiple regulating resources in the distribution power grid. Firstly, regarding the impact of harmonics on line loss in the context of high proportion of distributed resource access, a distribution network line loss calculation model considering harmonic loss is put forward. On this basis, the reactive power regulation capability of multiple regulating resources is analyzed, and a distribution network reactive power optimization scheduling model is established with the objective set as the minimization of line loss and the maximization of static voltage stability. By developing the reactive power optimization strategy of multiple distributed resources such as multiple adjustable load, distributed power supply, energy storage and reactive power compensation equipment, the goal of minimizing the system line loss under the comprehensive consideration of the static voltage stability requirements of the distribution network is achieved. Finally, through the simulation analysis of the improved IEEE 33-bus system, the results show that the full interaction of multiple regulating resources can effectively improve the system voltage stability, reduce the system loss, and ensure the secure and economic operation of the distribution network.