This work aimed to gain an insight into the influence of the dynamic component of vehicle load (caused by pavement roughness) on the dynamic stress responses in poroelastic subsoil. By introducing an analytical solution to the three-dimensional dynamic stress in the saturated poroelastic half space subjected to a harmonic rectangular moving load, the solutions of multi-layered saturated poroelastic half space under moving loading were derived using the propagator matrix method. Numerical results were obtained by performing inverse Fourier transforms. In the case of rough road on the saturated poroelastic half space computed by this method, the numerical results were obtained and used to analyze the influence of the dynamic component of vehicle load (caused by pavement roughness) on the dynamic stress responses. The results show the advantages of multi-layered poroelastic half space computing model and the stiffness of soil is important to dynamic stress responses. The speed and frequency effect of this load affect dynamic stress in subsoil dramatically. In the cause of the subsoil with thick and stiff pavement, the maximum value of shear stress caused by dynamic component is larger than those caused by vehicle weight. And the wavelength of rough pavement have an important effect on the dynamic stress responses, specially for short wavelength pavement roughness. In a model of a fast moving car with four wheels, remarkable vibration is happened caused by pavement roughness and the foundation vibrates more dramatically as the wavelength is shorter.