Abstract: To obtain the dynamic parameters of the group silo for more reasonable seismic design, the model of the silo with cylinder supporting structure of a grain storage in Shanghai was made and the environmental excitation test was carried out. Considering the symmetry of the group silo model and the finite element modal analysis results of the model, the key measuring points, general measuring points and reference points were arranged at the position with large vibration response of the silo, and the acceleration response of each measuring point was obtained. Then, based on the modal parameter identification theory, introducing the transformation matrix, and solving the eigenvalue problem of the system matrix, then the inverse transformation was carried out to identify the first four order dynamic parameters of the group silo model. The identification parameters were compared with the results of finite element modal analysis and peak picking method. The frequency error of each order was less than 7%, and the curve of each order mode was in good agreement. Further analysis of the vibration mode curve of individual silos showed that storage materials and the constraints between single silos had a great influence on the vibration modes of each order of the group silo. It is recommended that at least the first three modes should be used for seismic analysis in the seismic design of the group silo, and it should be designed in layers from outside to inside, and each layer should be designed according to the corner silo with full-filled materials.