Abstract: An approach combining the finite element with boundary element method is proposed to calculate the vibration and sound radiation of submerged double cylindrical shells in different conditions (considering and neglecting the coupling of the ribbed plate between inner and outer shells and fluid between inner and outer shells under two kinds of conditions). The coupling effects on the vibration and sound radiation of submerged double cylindrical shells is analyzed by comparing the numerical results in two perspectives: mean velocity level and radiated sound power level. The result indicates that the coupling has little influence on the vibration and sound radiation, and the less space between the two shells, the thinner the rib is, and the smaller radius of the inner shell is, the more negligible the coupling effect will be.