Abstract: Through programming in Matlab,the relationship between material parameters,including elastic modulus and compressive strength,with bending rigidity and compressive strength of foam-core sandwich composite is established on classic beam theory and sandwich panel theory.Meanwhile,the relationship between material parameters,including longitudinal-wave velocity,attenuation coefficient and loss factor,with underwater insertion loss of foam-core sandwich composite has also been taken into account by using transfer matrix method.Based on these,an overall design on mechanical and underwater acoustic properties is made by using the multi-objects optimization algorithms of NSGA-II,and a feasible overall design method of mechanical and underwater acoustic properties of foam-core sandwich composite is proposed.