72 sets of shear tests have been carried out by using a self-designed indoor anchor-soil interface shear test device to simulate the pull-out process, followed by an in-depth study on the effects of three factors on the shear characteristics of the anchor-soil interface, including the presence or absence of preloading, the moisture content of the soil and the degree of compaction. The results show that the shear stress of the anchor-soil interface increases positively with the shear displacement, while with the shear displacement reaching a certain value, the anchor-soil interface gradually weakens or destroys, meanwhile the shear stress decreases with the increase of shear displacement of anchor-soil interface. The water content and compactness of soil sample have a very important influence on the development of ultimate shear stress. The soil with water content equal to or slightly greater than the optimal water content is conducive to the improvement of ultimate shear stress; the greater the compactness of soil, the higher the ultimate shear stress. Under the preload condition, when the vertical pressure is lower than the preload in the shear test, the preload has a significant enhancement effect on the ultimate shear stress of the anchor-soil interface, while with the increase of the overburden pressure, the increase effect of the preload gradually decreases, with even the disappearance of the phenomenon that is not conducive to the exertion of the ultimate shear stress.