Abstract: For the CFG pile composite foundation, the setting thickness and modulus of cushion have a greater effect on the bearing and deformation characteristics of composite foundation. In this paper, the three-dimensional elastic-plastic numerical analysis model of CFG pile composite foundation is created, and the variation in the composite foundation settlement, settlement of pile, cushion compression and the pile-soil stress ratio and other parameters are examined when cushion of different thickness and modulus are used. The results show that the composite foundation settlement and cushion compression increase with the increase of the thickness of the cushion, decrease with the increase of cushion modulus; the effect of cushion thickness and modulus on settlement of pile is little; pile-soil stress ratio decreases with the increase of the thickness of the cushion, increases with the increase of cushion modulus. The other parameters of CFG pile composite foundation can further be respectively calculated and analyzed with this model. The results can provide the theoretical basis for design and construction of composite foundation.