Single-layer cylindrical shells are common structural form of underwater vehicles, which have more advantages than double-layer cylindrical shells regarding hydrodynamic noise control. With the increase of speed, however, the hydrodynamic noise of single-layer cylindrical shells cannot be ignored. This paper establishes the vibro-acoustic coupling model of a finite cylindrical shell fully immersed in infinite ideal water medium. On the basis of the comb function, the hydrodynamic noise calculation method for finite cylindrical shells under external turbulent boundary layer (TBL) excitation is established using correlation function and power spectral density function. The comb function method and the direct expansion method are used to establish the TBL wavenumber-frequency spectrum, respectively. The influence of the two methods on the excitations and displacements of the cylindrical shell in the calculation are analyzed. Furthermore, the sound radiation powers determined by the two approaches are compared with that of the statistical energy method. The results indicate that the comb function method produces different power spectrum density functions of TBL excitations and cylindrical shell displacements from the direct expansion method. The sound radiation power of finite cylindrical shells calculated by the comb function method has better agreement with the results of the statistical energy method in the medium and high frequencies, indicating that the hydrodynamic noise computation of finite cylindrical shell based on the comb function is more accurate. The effects of various speeds and shell thicknesses on the sound radiation power of finite cylindrical shell under TBL excitations are also compared. The results comply with the general law of hydrodynamic noise.