In the early 1980s, anchor cable reinforcement engineering required the installation of observation anchor cables, and the reinforcement of large deformation rock masses required the use of unbonded anchor cables. The engineering needs led to the emergence of unbonded anchor cables in China. At that time, there was no unbonded steel strand, and only smooth steel strands could be used for self-made production. Therefore, unbonded anchor cables were very non-standard. In the early 1990s, the standardized structure and construction technology of unbonded anchor cables were introduced into domestic hydropower construction, and were quickly promoted. However, in engineering applications, it is too simplistic to replace the double layer isolation layer with a single layer, and to replace the protective cap filled with anti rust grease with concrete or cement mortar at any time, which is difficult to ensure its permanence and poses a hidden danger to the safety of the project. The steel strand of the unbonded anchor cable is not bonded to the surrounding rock, and the reinforcement of the anchor cable to the rock depends entirely on its tensile force. The tensile force of the anchor cable only depends on the clamping force of the clip on the steel strand. Under the high stress action of hundreds of years, the clip and the section of steel strand it holds produce creep and corrosion, which will inevitably reduce the support force of the anchor cable to the rock. In the reinforcement of highway slopes with unbonded anchor cables, there has been more than one project that has failed due to the impact of rainwater on wind fossils and soil under the grid structure, causing the anchor cables to lose tension and the slope to lack support force