Abstract: When the inlet and outlet of fan system is connected with long pipelines, the structural vibration noise is the main component of the external radiated noise. In fact, the fan casing noise induced by unsteady flow is a typical fluid-solid coupling noise, and the vibration source is usually obtained by the unsteady flow field. To control the vibration noise of fan volute casing, a vibration noise optimization control method based on the Design of Experiment (DOE) method is proposed, the thicknesses of the volute walls, including front-wall thickness-T_F, side-wall thickness-T_S, and back-wall thickness-T_B, are taken as design variables, and the acoustic power on the volute surface is taken as the optimal objective function. The study shows that when the volute total mass remains constant, the radiated sound power on the surface of volute can be reduced to some extent after optimization, and the maximum reduction of 6.23 dB appears at the fundamental frequency.