Abstract: Through the calculation of the influence coefficient of layered medium, it is concluded that the data recorded by the underground resistivity observation system of Yangyuan seismic station mainly reflect the resistivity change of the medium layer where the device is located, and reflect the resistivity change of the deep medium. By comparing the observation curve of underground resistivity with rainfall and air temperature, it can be seen that underground resistivity has strong ability to suppress surface disturbance, stable change form and small annual variation range, which can highlight the anisotropy change under stress, which is conducive to the analysis and discrimination of seismic anomalies