Water damage in asphalt pavement is related to the interaction between cracks and hydrodynamic pressures caused by the vehicle. A 3D finite element model of the hydraulic crack in asphalt pavement was built to analyze the crack propagation character under vehicle load. The influence of asphalt pavement structure parameters, vehicle speed and crack geometric parameters of hydraulic crack were discussed. Then the differences, between aqueous cracks and cracks without water, were compared. The research results had the guiding meaning for anti-water damage design of asphalt pavement.