GFG composite foundation is an effective method of handling soft ground and is widely applied. Analyzing the side-pile effect of CFG composite foundation by finite element analysis program and discussing the effect of subsidence, stress in soil mass and bearing capacity of the side-pile to CFG composite foundation. The analysis indicates that the side-pile confine the extrusion of soil and diminish vertical displacement. Meanwhile, side-pile augment the effective extension of additional stress, could enhance bearing capacity and promote exertion of the bearing potential of the soil among the piles.