Abstract: By establishing the finite element model of gasholder ribbed shell structure, modal analysis is implemented, and then the first six order vibration modes is selected. The morphological characteristics of the vibration modes and the characteristics of the fundamental frequency are analyzed. Based on the bending vibration and shear vibration calculation principle of cantilever cylinder, a simplified calculation formula of basic cycle of gasholder structure is deduced. By using seismic code and FEM software respectively to analyze the modal decomposition response spectrum of gasholder structure, elastic dynamic response data are obtained, and the seismic performance of gasholder structure is verified, which can meet the requirements of specification under frequent earthquake action.