Owing to fluid characteristics of hydraulic structure seismic response, analysis method of this problem considering fluid-solid interaction is pointed out. And seismic response of vertical plate in the water was taken as an example to show how to solve this fluid-solid interaction system and analysis the features of it. In the analysis, effects of wave frequency and water depth were considered. The results indicate that incompressible fluid model based on Arbitrary Largrange Elurian description is enough to simulate motion of fluid domain and insure computing convergence in the analysis. It also shows that peak value of structure dynamic response is larger as the consideration of fluid-solid interaction. Water depth has great effect on fluid-solid interaction and has clear nonlinear feature.