Abstract: Study on the stability evaluation and treatment mesaure of lhigh and steep slope with strong weathering phyllite in Xunwu segment of National Highway 206, the characteristics of the deformation and the geological structure are analyzed. Based on the study and analysis, the evaluation of the stability is provided. The mechanical characteristics of the landslide are the important factors when the slope is analyzed. According to the analyzed data of the stability, the remaining declined force is calculated at the F_S=1.3 and the treatment measures are provided.