A periodic pipe system composed of steel pipes and rubber hoses with the same inner radius is designed based on the theory of phononic crystals.Using the transfer matrix method,the band structure of the periodic pipe is calculated considering the structural-acoustic coupling.The results show that longitudinal vibration band gaps and acoustic band gaps can coexist in the fluid-filled periodic pipe.The formation of the band gap mechanism is further analyzed.The band gaps are validated by the sound transmission loss and vibration-frequency response functions calculated using the finite element method.The effect of the damp on the band gap is analyzed by calculating the complex band structure.The periodic pipe system can be used not only in the field of vibration reduction but also for noise elimination.