<p>Cracking and dislocations in the road surface, in addition to the prominent settlement and deformation of the subgrade, are the result of poor subgrade conditions and heavy traffic. These hazards pose a major threat to the normal operation of the roads and the safety of residents. This study uses Abaqus numerical analysis software to establish a 3D model of the road structure system. The indoor shear strength of the actual roadbed soil is evaluated, and the dynamic response law and settlement deformation characteristics of the loess subgrade are examined under different moisture contents, dry densities, and vehicle loading conditions. This study strives to provide a reference for disaster prevention and mitigation on urban roads in the loess subgrade. Results show that under the action of vehicle loading, the vertical strain and vertical displacement of the loess subgrade decrease along the depth direction. The attenuation rate changes, exhibiting multiple modes, from shallow and fast to deep and slow. The influence depth of a standard vehicle with a 15-stage wheel load is approximately 4.5 m under the road surface, and plastic deformation diffusion occurs along the depth direction. The cumulative settlement deformation of the loess subgrade shows a gradual increase with the accumulation of cyclic vibration, exhibiting large deformation in the early stage and stable development in the later stage. Thus, water control and load control can help reduce the rate of road disasters by minimizing loess subgrade deformation and settlement.</p>