For the vibration characteristics of cylindrical shells, a cylindrical shell treated with partial constrained layer damping is presented. Its dynamic equation is established based on the constitutive equation of elastic and viscoelastic materials by energy method. The influence of damping patch’s key parameters on the shell vibration characteristics is investigated. A multi-objective function is established, in which the objective of optimization are the loss factor of the first three modes, and the design variables are the number of damping patches and the gap in axial and circumferential direction, the thickness of the damping layer. An optimization of the cylindrical shell with simply supported edges is executed using multi-objective genetic algorithm. By analyzing and comparing the modal frequency changes，the various of loss factors and the amplitude-frequency response of cylindrical shell before and after optimization, it is shown that a reasonable layout of damping segment can reduce the introduction of the damping materials effectively, and can achieve a better damping in conditions that the inherent vibration properties of the cylindrical shell does not change too much.