Abstract: Based on the assumption of equal strain and stress concentration effect, a model was built to study the consolidation behaviors of CCSG (low-grade concrete-cored sand-gravel) pile composite foundation, which is a new multi-component composite foundation. The coefficients of the horizontal permeability in the smear zone, the radial flow inside the sand-gravel shell and the undrained property of concrete-cored pile were taken into account to derive the general analytical solution for consolidation. The results show that the Terzaghi one-dimensional consolidation solution and the consolidation analytical solution of ordinary composite foundation were special cases of this solution. Curves of the average consolidation degree of the composite foundation under three horizontal permeability coefficients in the smear zone and various non-dimensional parameters were observed using the program based on the theoretical formula. The analyzed result shows that the consolidation of composite foundation was largely effected by the changes in the horizontal coefficients of permeability in the smear zone and non-dimensional parameters. The analytical solution was finally validated with the actual measurement data.