The underwater vibration response of cylindrical shell with different ribs and bulkheads arrangement was calculated by using the finite element method and the boundary element method. By means of the wavenumber spectrum method, the vibration and sound radiation of structural waves with different wave numbers were quantized in combination with the acoustic radiation efficiency of the regular wave of a shell. Based on the vibration theory of periodic and aperiodic structure, the mechanism of influence of the ribs and bulkheads arrangement on the vibration and sound radiation characteristics of cylindrical shell was revealed. Through the study it can be found that the shell with aperiodic ribs and bulkheads has better underwater vibration characteristics, which are more affected by the circumferential vibration of shell. And the acoustic radiation characteristics of a shell with aperiodic ribs and bulkheads are not necessarily better than those of a cylindrical shell with periodic ribs and bulkheads.