The invention discloses a reactive power planning optimization method of a high voltage distribution network. The reactive power planning optimization method of the high voltage distribution network is characterized in that the capacity of a reactive compensation device is planned reasonably on the basis of a determined net rack, reactive power flow of the distribution network is reduced, and it is ensured that the distribution network supplies high-quality power to users safely and economically. The specific implementation steps are shown in the figure of the abstract. The reactive power planning optimization method of the high voltage distribution network is used for power grid departments to reasonably allocate construction of the reactive compensation device of the high voltage distribution network.