Impedance frequency response method for measuring corrosion state of grounding network of transformer substation

The invention relates to an impedance frequency response method for measuring the corrosion state of a grounding network of a transformer substation. The method comprises the following steps of: 1, calculating impedance frequency response curves between grounding down leads at different positions and under different corrosion states of the grounding network of the transformer substation by numerical simulation and a corresponding frequency point impedance numerical list; 2, actually measuring and drawing the impedance frequency response curves at the different positions of the grounding network; 3, querying the impedance frequency response curve which is at the same position of the grounding network of the transformer substation and is measured every year; and 4, comparing original input data which are obtained in the step 1, the impedance frequency response curves which are at the different positions and are obtained in the step 2, and the impedance frequency response curve which is at the same position, is measured every year and is obtained in the step 3, estimating the corrosion states of the grounding network, and giving the corrosion level of the grounding network and the equivalent diameter of a grounding body. The method has the advantages that: excavation and soil sampling of the grounding network are not required; the working load of corrosion measurement of the grounding network of the transformer substation is reduced; the cycle of the corrosion measurement of the grounding network of the transformer substation is shortened; and the judgment accuracy of the corrosion level of the grounding network of the transformer substation is improved.