Abstract: At present, there are few studies on the mechanical properties of large-span concrete-steel corrugated pipe arch culverts. For this reason, taking the large-span circular steel corrugated pipe culvert as a comparison, the difference in mechanical properties between the large-span arch culvert and the large-span circular culvert is revealed, and the change law of mechanical characteristics and the effect of EPS board load reduction were compared and analyzed.The results are as follows. The distribution laws of the mechanical properties of the two types of culverts are basically the same, and the most unfavorable points are located on the culvert side and culvert top. Larger, the unloading is better and the advantage is more obvious under high fill. The transfer law of the soil pressure of the two types of culvert structures is the same, that is, from the center to the two sides, from the pipe culvert to the surrounding soil. It is transmitted to the foundation, so that the tangential stress of the culvert side trough is small. The vertical earth pressure and the maximum equivalent stress of the structure become nonlinear changes after the EPS slabs are laid in the two types of culvert structures. The former has the same load reduction effects, while the latter arch culvert reduces more and thickens after the slab thickness is 30 cm. It has little effects on both. Therefore, the mechanical properties of the large-span arch culvert and the unloading effect of the EPS board are better than those of the round culvert of the same span.