The coupled water-load action is one of the primary factors of initial failure for asphalt pavement. Using the finite element numerical analysis software ABAQUS, based on elastic plastic material hypothesis, the 3D finite element coupled fluid flow and stress model of asphalt pavement in the case of rainfall infiltration was established. What's more, the loading type, boundary condition and material parameters were listed out. Then, the numerical simulation under uniform vertical moving loads was given, the comparison and analysis of spatial distribution for asphalt pavement between coupled condition and dry condition were carried out, which included 3D stress, vertical displacement and pore water pressure. The results indicate that under coupled fluid flow and stress condition, the dynamic response of 3D stress is different from that of dry condition, so the force behavior of asphalt pavement is more dangerous and it is more likely to have structure damage.