The BG(band gap) theory of PCs(phononic crystals ) is introduced into the structure design for equipment shell, and the cylindrical shell section of equipment was designed to be periodically composite material structure. Utilizing the model synthetic technology, the transmission characteristics of flexural vibration in the periodic and the non-periodic cylindrical shells are calculated and compared. Results show that, in the periodic shell structure, there exist several flexural vibration BGs; whereas in the non-periodic shell, these BGs will disappear. Further, a periodic cylindrical shell made of composite laminated material is constructed and its vibration properties of are investigated. As expected, the existence of BGs in such a periodic structure is guaranteed and flexural vibration transmitting in this system will be attenuated apparently. Finally, as for practical engineering application, vibration properties of a complex equipment shell of which has periodic section in it are studied. Calculation results reveal that the introduction of BG theory into the vibration control for engineered equipment shell is quite feasible, since the complex equipment shell with locally periodic structure always maintain the BG characteristics.