Abstract: For 5 ? 5 three-dimensional composite foundation pile group, using the finite element analysis software ANSYS for the analysis of dynamic characteristics, in the calculation model, the pile, soil between piles, foundation and cushion are assumed to be linear elastic models, and the feedback effect of the upper structure is also considered. Numerical simulation is employed to study the structural vibration characteristics. The time history analysis method is used to analyze the earthquake response of composite foundation. The magnitude of displacement and internal forces and distribution of the composite foundation-foundation-superstructure under different seismic excitations are studied. It may provide reference for seismic design of structures.