Abstract: For culverts under the high-stacked soil, multi-conditional experimental comparison about reducing-load impact of laying flexible material EPS on the top and sides of the culvert is done. The result indicates that effect of reducing soil pressure on the top and side of culverts is distinct. At the same time, it can resolve uneven settlement of road surface induced from culverts under embankment, and improve uneven longitudinal distribution of vertical soil pressure and settlement of culverts. Based on comparison of results obtained by the authors and by FEM with measured soil pressure, these data are comparatively close to each other. The results can be used to design practical project as a basis of design criterion and design regulations.