This　study　describes　how　to　simulate　the　wind　field　accurately　by　the　Computational　Fluid　Dynamics　(CFD).　Our　main　efforts　are　focused　on　introducing　the　corresponding　control　equation,　and　analyzing　the　process　how　the　wind　has　effect　in　terrain.　CFD　model　will　be　applied　to　the　wind　field　over　the　complicated　terrain　in　the　forest　fire　instead　of　flow　field　calculation　of　aerodynamics.　According　to　the　result　calculated　with　CFD　model,　it　will　be　simulated　with　a　computer　to　realize　visualization.　By　simulating　the　wind　field　of　the　actual　field　landform　which　is　located　in　East　Bao　Mountain,　Longyan,　Fujian　province,　this　work　raises　the　question　associated　with　the　wind　in　structure.　Therefore,　it　is　necessary　to　analyze　the　three-dimensional　wind　field　over　the　complex　terrain　which　will　furnish　a　feasible　analysis　method　for　the　future　of　the　forest　fire　simulation.