Abstract: Discussed are the influence of output saturation on active vibration isolation and sound radiation control and the method for saturation alleviation. A time domain model describing the coupled vibration of fluid-structure systems is first established by the FEM/BEM approach, in which the added mass of fluid is modified to ensure the accuracy of the natural characteristics of the coupled system. With the time domain model, an adaptive vibration control strategy with saturation alleviation is constructed. Simulation is conducted with a single-degree-of-freedom model connected to a simply supported stiffened plate, which is rigidly baffled and coupled with water at one side. The results have demonstrated that the scheme for saturation alleviation can substantially improve the performance of active isolation of vibration and reduce the radiated sound from the stiffened plate.