A highway route in Guizhou is located on an ancient landslide deposit. There is a village on the platform of the landslide deposit. The amount of the slide body reaches 996000 m
3. Most of the route has been completed in the way of bridge mode, and the slope needs to be excavated locally. During the construction of the road, the original balance conditions of the landslide is changed, which may jeopardize the safety of construction and operation. Based on the identification of the geological environment conditions, geological structure and deformation sliding mechanism of the landslide, a geological structure model is established. Its stability is analyzed by using the simplified Bishop method, and the prevention and control plans are suggested.