In this paper, a 2D bidirectional wavecurrent coupled model in Haitan Bay was set up based on the MIKE 21 SW wave module and FM current module. The effects of wave and current interactions were incorporated by extracting the radiation stresses from wave simulations into FM model, and extracting the water levels and velocities from flow simulations into SW model, respectively. The flow fields and wave fields in Haitan Bay under pure current and pure wave condition were simulated respectively, and calibrated by the field measured tidal flow and wave data. Then, the well validated models were employed to model the flow fields and wave fields under wavecurrent interaction. The results show that the wavecurrent interaction has a great influence on both flow velocity and wave height and the wave height significantly increases if the wave and current are in the opposite direction; the decay rate of wave height in the inshore area in both flood current and ebb current is in accordance with that in pure wave condition; the position for the wave height that begins to decrease in ebb current is obviously earlier than that in flood current; the radiation stress has a significant influence on the flow velocity in the wave breaking zone.