Polyurethane foam material, with its rapid expansion, high strength, lightweight, and water-repellent characteristics, has significant engineering value in temporary repair works such as emergency road clearance after water damage. To study the mechanical characteristics of polyurethane materials for subgrade under cyclic loading, axial cyclic loading and unloading compression test , and tangential cyclic shear test were carried out on polyurethane samples containing interface, and the change rule of stress-strain law and macro and micro damage characteristics of polyurethane samples wereanalyzed under different loading frequencies and loading ranges. The results show that: The strain of polyurethane samples increases and then decreases with the frequency of axial loading, and continuously increases with the upper limit of axial stress loading (up to 7%~8%); the maximum strain increment induced by axial stress loading is four times the corresponding value for the loading frequency, which has a more significant effect on the sample strain; under axial cyclic loading and unloading, the sample is mainly subjected to compression-shear damage along the cemented surface and tensile-shear damage along the vertical fissure-cohesive surface, the increase in the loading range of the tangential force causes a significant increase in the deformation of sample (up to 5%~6%), and eventually compression-shear damage along the cemented surface occurs; increase a certain amount of axial force (should not exceed 90% of the uniaxial compressive strength) can be better compaction of polyurethane materials, which can improve its shear performance, in engineering applications, it is advisable to avoid placing polyurethane materials in a cyclic shear stress state when the axial force is small or there is no loading.