The invention relates to a grounding network design method for reducing the impact grounding resistance of the pole grounding network. The soil resistivity in the surrounding a pole is measured to inverse the layered state of the soil, CDEGS software is utilized to determine distribution of flexible graphite vertical earth electrodes in the pole grounding network via a lot of computation, a 3D transmission-line power grounding network model is established, different designs of the pole grounding network are realized, and the impact grounding resistance of the grounding network is reduced to the largest extent. According to different landform conditions, 3D grounding network design is carried out on each pole, the impact grounding resistance is reduced to the largest extent, reference for pole grounding network construction is provided for power departments, and the method is suitable for poles of different voltage levels.