Abstract: Whenshan-Chenshan highway is located in Kemen Port in Lianjiang, Fujian province, surrounding Luoyuan Bay, and there is a high rock slope, with a complicated engineering geological condition, to be crossed in the segment of K5+000~K5+140. There are two sets of dominant structural plane developed in the high slope rock mass, and stability of the slope is influenced by them both. Therefore, it is necessary to evaluate the stability. By Stereographic projection, the stability of the natural slope is analyzed. Furthermore, to approach a reasonable slope ratio for excavation, the method is used again. After the cut slope is excavated, the effect is proved to be perfect.