Tongchuan-Huangling Class I Highway is located in the Weibei Mountain Area of the northern edge of Guanzhong Basin. It is also the important links between Guanzhong Plain and Loess Plateau in the northern Shaanxi. This highway attracts more attention because of its frequent occurrence of landslide due to the special geography and geological conditions. The data on landslide surveyed along the alignment shows that substance of most slip belt is wet and is in saturated condition. The landslide is located on the top part of fault. Under function of fault and fold structure, the rock body is crushed, and the underground water corridor forms, and control the formation and development of landslides. Strengthening the soil of slip zone refers to the physical strengthening method through baking, freezing and grouting in order to improving the strength of soil of slip zone so as to stabilize the landslides.