Abstract: In this paper, the sediment scouring and silting in Jiaozhou Bay are simulated before and after the construction of Jiaozhou Bay Bridge. The current velocity and flow direction near the bridge at typical times are discussed. Compared with the simulation results of flow field in the bay before the bridge construction, it can be found that the bridge construction has little effect on the overall current patterns in Jiaozhou Bay. The changes of hydrodynamic force in Jiaozhou Bay due to the construction are mainly in area near the bridge piers. The results of numerical simulation of scouring and silting on the bridge construction show that the trend of scouring and silting is basically the same, but the scouring and silting near the bridge piers change remarkably. The siltation strengthened area appeared on the north and south sides of the piers before the bridge construction, and the scour strengthened area appears on the east and west sides of the piers after the construction. The scour intensity increases obviously in the sea area where the larger navigable span crosses.