Abstract: A numerical analysis is studied on the construction, runtime and earthquake condition of composite ground reinforced by stone columns. The calculated results indicate that the stone columns have significant effect on drainage of the excess pore pressure under construction and runtime; when the pile length is larger than 6 m, the maximum pore pressure changes slowly; when it is larger than 10 m, the settlement under embankment and horizontal displacement under slope toe change slowly. Under earthquakes the maximum acceleration at the top of the pave is larger than that at the bottom of the model; in reinforced scope, the horizontal stiffness of composite ground is larger than that of natural foundation; in the whole ground, the vertical stiffness of composite ground is larger than that of natural foundation, and the maximum displacement is larger in large stiffness ground; the toe position and slope of embankment are easy to be liquefied under earthquakes, but stone column composite ground can reduce the possibility of liquefaction.