Abstract: Based on the shallow water equation and the Boussinesq hypothesis,the tidal energy development model is established by the momentum sink approach with Delft 3D-Flow module.The model is established by the nesting method and the domain decomposition method respectively,and verified by the measured data from Zhaitang Island sea area.By comparing the calculation precision and effects on the environment of the two models,the results show that the domain decomposition model can effectively reduce the computational expense,and is suitable for studying the effects of tidal current turbine array on large-scale flow field,as well as tidal current energy under complex terrain.