Based on the local deformation theory, the anchorage mechanism of anchor-grout interface failure type is analyzed and studied. The grouting body and surrounding rock mass regarded as a whole with zero relative displacement. The stress distribution of the shear stress and axial load on anchor-grout interface is obtained by determining its main influential coefficient (r and k_s). Via the comparison between the numerical simulations by Flac 3D and the experimental results, the rationality of this method was verified. A virtual coefficient T is used to describe the interface properties of the bolt and the grouting body and its influence is analyzed. The results show that the anchoring effect can be enhanced by increasing the length of the anchor in a certain range. However, excessive increase of the bolt length has marginal effect on shear stress and axial load. With increase of the anchor radius, the shear stress peak of the anchor surface is non-linearly reduced and range of action is increased. To avoid stress concentration, the anchor rod with small radius should be avoided. The virtual coefficient T can reveal the difference degree of anchor grouting interface. With the increase of T, the shear stress on the anchor grouting interface increases, while the homogeneous degree of the stress and the action length of the axial load reduce. By taking appropriate T value the anchoring effect is best. The effect of T value on the anchoring mechanism of bolt is significant.