The hydro-geological conditions are complicated in the separated tunnels of Changji highway,seepage control was a key in the tunnels excavation.Taking the separated tunnels engineering in Qinggangshang as example,in which groundwater are developed in the fractured rockmass,based on theory of equivalent continuous medium,the numerical simulation of seepage flow was conducted by three-dimensional fluid-solid interaction model and FLAC3D.On the basis of thre results of analysis and computation,places at which water seepage occurs before and after the tunnel excavation are presented,and some supporting measures are suggested for different surrounding rock,so as to provide a technical support for the safety of the tunnel construction.