The salt spray gathering in the grillage space of piled beam-slab wharf easily makes the beams corroded in the harsh marine environment,which can cause an adverse impact on the durability of structure.Using the fluid dynamic module CFD of ANSYS,we establish the three dimension model of grillage space of piled beam-slab wharf.For various vent forms,we analyze the wind speed and pressure in salt spray concentration area of piled beam-slab wharf,and optimize the vent setting based on the results of the dissipation effects for salt spray.The results show that the vent setting in the longitudinal beam could improve air flow distribution of grillage space effectively,and as the distance between the vent and two ends of beam was 1.2 meters the dissipation effect for salt spray is most significant.