Abstract: The existence of underground goaf can easily cause tilting and settlement of power towers, which is a major hidden factor in the safe and stable operation of power grid. To detect the mine goaf under the power transmission corridor is of great significance. When there is a grounding grid in the detection area, the grounding grid will have certain influence on the measured value. In this paper, the detection of mine goaf in the presence of a grounding grid is presented. Based on the theoretical analysis, the mathematical model is built, and the simulation model is conducted. The influence of the grounding network on the detection data was analyzed through different detection methods, and the influence rule of the grounding network on the detection data of the gob area was obtained. At the same time, the areas that have large impact on the detection value were divided, and reasonable suggestions were put forward, which can provide reference and guidance for the actual engineering work of goaf detection under the transmission corridor.