Abstract: Based on the theory of ship fluid-structure-sound coupling interaction, the engineering three dimensional program was explored to compute the entrained water mass of ship wet mode on the basis of Potential Flow Theor y. The calculated results were compared with the theoretical value, empirical value and numerical value of FEM to verify the validity and rationality of the program. A method of ＂sound balance＂ was proposed to analyz ze the coupling vibration of hull-base-equipment which is excited by ship-equipment-paddle as well as underwater sound radiation. The results show that the sound pressure of stem with engine location takes on peak-to-v alley tendency, which can be reduced through the optimum matching site. As for the selection of ships＂ main and auxiliary engines, the sound balance of hullbase-equipment as well as that of equipment needs to be con nsidered, and this method must give attention to multi-support excitation force ratio and the frequency ratio. This article aims to provide reference for acoustic design of hull structure.