In order to study the wave condition on sheltered waters behind permeable hydraulic structures, we simulate the wave propagation under given conditions using both the BW (Boussinesq wave) module of the MIKE 21 (DHI) and the SWAN model. Through the comparison between the two sets of numerical simulation results and three dimensional physical model results, we analyze the feasibility of numerical simulation about wave condition on sheltered waters. At last, SWAN model is used to simulate the wind wave field on water areas which is covered by the submerged breakwater on the extreme condition of 12-class Beaufort scale wind, and satisfactory simulation results are achieved.