Abstract: Affected by various external factors, the tensile force of prestressed anchorage structures presents loop and fluctuation characteristics in practical engineerings, which will cause severe impact on the inner anchoring section of the prestressed anchorage structures. On this base, PFC2D discrete element program was established for numerical simulation analysis of microscopic physical and mechanical changing characteristics of stress, porosity, angle, etc. of different interfaces locations for prestressed anchor cable under cyclic loading. The results showed that: at locations of the front-middle, the grouting body near interfaces were divided into tensile stress area of the inside part and compressive stress area of the outside part, and two locations of y-direction stress concentration were located at the two end of inner anchoring section; The interfaces had the feature of progressive failure and the characteristic of shear stress peak shifting; While loading finish, particles at different locations of interfaces basically generated clockwise rotation angle, but at two locations of y-direction stress concentration, the particles rotation angle, which was very small at the other locations, was very large; At y-direction tension and compression stress boundary, the particles spinning direction showed instability characteristic and the ultimate rotation angle was small.