Most of the foundation soil in airport engineering belongs to unsaturated soil. The subsidence law and stress change rule of unsaturated soil foundation in the filling phase of embankment were analyzed by the software of Midas/GTS. The one-dimensional consolidation theory of unsaturated soil and the Van Genuchten model of soil water characteristics were considered in the programs. The results showed the stress decreased with depth increased and they could be seen as two straight lines. The interval time in filling phase of unsaturated soil had little impact on the stress. The depth-settlement curves had big difference between the overall filling and layered filling that the settlement of layered filling was far greater than the overall filling. In the layered filling, the curves of depth-settlement were similar with different interval time that could be approximately separated into two phases and the largest settlement appeared on the surface of the ground.