It is difficult to obtain the analytical solution of a nonlinear consolidation partial differential equation. In order to solve this problem, the consolidation time is segmented into small intervals and the parameters of soft soil and stone columns are assumed to be constants at any time interval. Then, the governing consolidation equation of the stone column composite foundation is built and solved at each time interval. The calculation parameters and initial conditions of the computing unit can be determined by the calculation results of a previous time interval. Finally, consolidation calculation is conducted for the composite ground, with consideration of the nonlinear characteristics of the stone column and soft soil. On this basis, the nonlinear consolidation properties of composite ground are analyzed. The results show that the consolidation rate of the stone column composite ground decreases with the increase of Cc / Ck.