Abstract: Based on the relationship between soil resistivity and soil moisture content, the soil resistivity profile measured by high density electrical method can be quickly transformed into water content profile, which is of great significance for the continuous monitoring of soil moisture content. In this paper, the unsaturated loess in Heifangtai, Yongjing, Gansu Province is taken as the research object. The indoor one-dimensional resistivity test is carried out by four electrode method. The time characteristics of the resistivity are analyzed, the accuracy of the Loess resistivity test is improved, and the relationship between the resistivity and water content of the loess in Heifangtai is established. The results show that under the same dry density, in the process of moisture absorption and dehumidification, the moisture content and resistivity of loess show an exponential relationship, and both of them have a good correlation. In the process of increasing moisture content, the resistivity of soil decreases gradually. Under different dry density conditions, the resistivity and water content of loess have a good correlation, and with the increase of water content, the resistivity value gradually decreases until it tends to be stable. With the increase of dry density, the sensitivity of soil to water decreases.