Abstract: There are many loess gully natural high and steep slopes in Shanxi Province,Slope stability is an extremely important issue in the construction of highways, railways and other projects. If not handled properly, it will result in the loss of human and economy. This paper analyzes the slope failure of external and internal factors, currently used for slope stability analysis are sunmaarized to provide a theoretical basis for slope stability designs of practical engineering, slope stability analysis and slope treatment.