Abstract: The method of using the stone-column in soft clay ground treatment has been applied widely in subgrade engineering. This study proposes a conversion method, using the unequal strain assumption theory, to obtain the equivalent plane-strain model of the unit cell. Firstly, the plane models of the pile-soil unit, based on equal strain assumption and unequal strain assumption theory, are established by ABAQUS.Secondly, the simulation results of these two models are compared with a reasonable axisymmetric result, and the results show that the unequal strain assumption theory is more suitable. Finally, a plateau wetland highway soft soil subgrade engineering is simulated using these two models, and the results further prove that the transformation model based on the unequal strain assumption theory is more reasonable.