To construct an artificial island in Qiongzhou Strait, which is under a fairly complex hydrodynamic environment, we shall not only consider the stability of the artificial island itself, but also recognize the changes of flow field in the surrounding waters and sediment erosion and deposition caused by the construction of the artificial island. In order to study the impact of the construction project, we research the change of tidal current field after implementation of Ruyi artificial island project based on the physical simulation of tidal current and sediment, and obtain the scope of strength of impact. We also analyze and predict the silt erosion and deposition in the sea area which the project locates, and draw the conclusion that “the construction of the artificial island exerts some impact on the surrounding waters”.