Abstract: The paper, combined with engineering practices in loess area of west Shanxi, through field investigation and measurement, laboratory experiments, numeric calculation, aimed at different slope height (8m, 16m, 24m, 32m, 45m), using analogy, anti-algorithm, literature and numeric calculation to carry out analysis and study, derived the optimal rate of loess slope with different height.The results have been used in construction projects of the area.It can save project investment, protect the geological environments in construction area, also provide reference for similar construction projects in other areas.