The large number of waste tires has led to increasingly severe pollution. The engineering application of waste tires is one of the ways to dispose of them. Waste tires have good engineering properties, such as high strength and corrosion resistance. Studying their role in subgrade construction is of great significance for guiding the construction of reinforced subgrades with waste tires. However, existing research mainly focuses on the reuse of tire fragments, and there is insufficient research on the reuse of whole tires. In order to further investigate the influences of filler types and geogrid reinforcement on whole waste tire reinforced subgrades, three model tests were conducted to analyze their load-bearing deformation behavior. Subgrade top-surface displacements, vertical soil pressures, and tire strains under different stress levels were analyzed. The research results indicate that the tire reinforcement layer is conducive to the distribution of additional stress, and as the load increases, the role of the tire reinforcement layer in distributing stress gradually enhances. Laying geogrids below the tire reinforcement layer effectively increases the overall stiffness of the reinforced zone and reduces subgrade deformations. The combined effects of the tire and geogrid increase the distribution angle of additional stress in the soil near the tire reinforced zone, and geogrids share some loads, reducing tire deformations.