Abstract: The paper analyzed the current characteristics of high rock slope and the predicament in treatment, summarized the advantages and disadvantanges of the quantitative evaluation of high rock slope stability. Taking a project next to the building of mountain slope as an example,it used strength reduction method to evaluate the slope stability, and studied the failure mechanism and form of mountain rock bedding high slope. With adaptation to local condition, the top of slope supporting structure selected the new GSS2 A active protection net system, the bottom of slope selected the foot wall and the arched frame masonry structure. The practice shows that the overall stability evaluation methods is suitable in the design of slope supporting, and the supporting structure is safe,economical and beautiful, convenient for construction. It provides reference for the similar slope treatment.