Abstract: The relative dielectric constant of artificial sandstone core was measured, and the relationship between relative permittivity and saturation, porosity and mineralization were studied in the frequency band of 20～1 000 MHz. The results show that the core's relative permittivity has a good linear relationship with saturation and porosity, and the mineralization has a great influence on the relative dielectric constant at low frequency. Based on the analysis of experimental data, combined with the existing dielectric saturation model and based on Maxwell-Garnett theory, a multi-frequency dielectric mixed interpretation model suitable for sandstone is presented.