Abstract:The vibration and sound radiation of underwater composite sandwich plate with visco-elastic core was established by variational method , the displacement field was described by discrete layers theory, the continuity of shear stresses and displacements at each interface was enforced to form transfer matrix which makes the system equations connect only the displacement components of the bottom plate, thereby reducing the dimensions of the equation and improving the computing efficiency, then the motion equation was solved by Rayleigh-Ritz method. To verify the proposed method, the calculation result was compared with the classical reference. The material and geometric parameters were concerned, and the main influence factors for acoustic radiation were obtained, which provide references for passive noise control of underwater structures