In this study, we collected the geological, electrical strata, and electrical sounding data from the Linfen seismic station in the Shanxi Province, China. According to this information, the electrical structure of the medium beneath the Linfen station was simplified as a two dimensional electric section. On this basis, a three-dimensional inhomogeneous finite element model was constructed, and the electrical structure of the strata in the study area was analyzed. The results show that the earth resistivity will increase with rainfall, which explains why the georesistivity in the Linfen station shows a high feature in the summer and a low one in the winter. In addition, the impact of rainfall on earth resistivity increases with depth, which is also concerned with media uniformity and geological factors. The rise of the water level in surrounding canals has little effect on the earth resistivity; therefore, it is believed that the gradual decrease of georesistivity since 2010 is not related to canals. The study has great significance to the interference factors of earth resistivity and possible earthquake precursors.