Soil conductivity characteristics are the main factors affecting the safety of power system grounding engineering, while the complex distribution of soil resistivity and its anisotropy often cause deviations in the evaluation of the actual grounding. This paper establishes the anisotropy model of soil resistance based on a microscopic perspective, improves the discrimination method of resistance anisotropy, and proposes the conjecture that the variation of resistivity anisotropy is caused by the difference of conductive medium connectivity in different directions. In this paper, the probability distribution of resistivity and the resistance anisotropy ratio are found to be distorted in specific water content intervals, and the trend of the distortion rate is consistent with it, combined with the critical conditions of sudden changes in soil resistivity. Moreover, the correctness of the conjecture is verified in this research. It is also found that there is more than a single conductive mutation interval in the soil, and one of them is at low water content in the high porosity model due to differences in the connectivity of the soil skeleton in all directions. This method can be applied to other studies of soil anisotropy, such as percolation, by changing the conditions and parameters.