A three-dimensional viscoelastic finite element model of asphalt overlay was constructed based on the viscoelastic characteristics of asphalt mixture, and dynamic loading tests were performed by using the finite element software ABAQUS. The results show that, a different and more complex mechanical response than that of elastic material is generated because of the viscoelastic characteristic of asphalt mixture overlay itself. The stress state changes with the loading and unloading process-a compressive stress is generated on the surface, and a tensile stress is on the bottom surface when loading. The unloading process is on the contrary. A residual stress will be generated on the surface and the bottom surface under the alternately repeated compressive stress and tensile stress. Furthermore, the residual stress decreases with increasing the temperature, while the relaxation capacity increases and the viscoelasticity decreases. This method gives a more accurate and scientific description on the mechanical behavior feature of asphalt overlay than treating the asphalt mixture overlay as an elastic material.