Abstract: Environmental parameters (e.g., wave design parameters) are necessary for the offshore engineering design. This study established a high-resolution wave-current coupled model for the sea area of offshore wind farm of Fujian Nanri Island, and further discussed the effects of water level and current on waves. The simulation results showed that compared with the single wave model, the significant wave heights obtained by the coupled model are more accurate. By analyzing the impact of wave current coupling on wave simulation results in the process of typhoons, we found that the spatial distribution of the impact of wave-current coupling on the maximum significant wave heights is significantly different. In the four typhoon processes of this study, the impact of coupling on the maximum significant wave heights in the project area can reach −1.0 to 1.0 m. The analysis of single point simulation results showed that the wave heights are weakened when the flow direction is in the same direction as the wave one, and are enhanced when the wave direction is in the opposite one. In addition, the wave current coupling also plays a significant effect on the wave direction and spectral peak period, which cause a wave direction variation of up to 20 degrees and a spectral peak period variation of up to 2 seconds, during typhoon 1319. Finally, this study clarified the importance of using wave current coupling model in reproducing wave extreme value, which can be used as a reference for offshore engineering design.