Combining the axisymmetric consolidation model and the equal vertical strain assumption, differential equations governing the consolidation of a composite ground with long cement-soil columns and short stone columns subjected to an instant load were presented. The corresponding analytical solutions were derived under single-drainage condition, including the solution of average excess pore water pressures in the interior of a stone column and subsoil around a cement-soil column, and the solution of overall average degree of consolidation of the composite ground. Then, the proposed analytical consolidation solution was verified via the comparison with the numerical solution by the finite element method. Finally, some main influencing factors were analyzed to investigate the consolidation behavior of the composite ground. The results show that the penetration ratio of the stone columns (ratio of stone column length to soil thickness) is a crucial factor affecting the consolidation rate of the composite ground, and the higher the penetration ratio, the faster the consolidation of the composite ground. It increases gradually with the increase of the permeability coefficient and area replacement ratio of the stone columns, as well as the area replacement ratio and constrained modulus of the cement-soil columns. For the situation of higher values of penetration ratios, the variation of the well resistance and the area replacement ratio of the stone columns has obvious influence on the consolidation rate. The change in the constrained modulus of the stone columns has a limited effect on the consolidation rate of the composite ground.