Abstract: Water plays a pivotal role in influencing collapsible loess foundation. In this article, the physical and mechanical parameters of loess and lime soil in Lanzhou are obtained through indoor geotechnical test. The effect of different structures to control lateral seepage in subgrade loess soil is studied through indoor model test. At the same time, the settlement of roadbed is monitored. The experimental results reveal that the permeability coefficient of the lime soil is much less than the coefficient of permeability of loess. After processed by lime-soil compaction pile and lime-soil impervious wall, the moisture content of loess is far less than the value that the lateral seepage control processing is not made. Collapsibility deformation of subgrade is obviously improved. The effect of lime-soil impervious wall is better than the lime-soil compaction pile. The test results can guide the collapsible loess subgrade seepage prevention effectively, and provide a new idea for collapsible loess foundation treatment.