Abstract: The different structure types of double cylindrical shell, i.e. variable thickness of pressure hull plate and frame configuration, were studied to analyze the effects of structure types on the sound radiation by applying ANSYS and SYSNOISE software based on the finite element and boundary element methods. The effects relating to variable structure types on the sound radiation were observed, the non-circularity of double cylindrical shell was also investigated on vibration and sound radiation from underwater structure. It is found that the non-circularity of double cylindrical shell may intensify the vibration of underwater structure, and that the non-circularity of shell section is bigger the radiation sound power is greater. This implies an important value for noise reduction of underwater vehicles.