Crowd　simulation　has　been　widely　used　in　virtual　building　evacuation,　crowd　behavior　drilling,　movie　making,　entertainment　and　many　other　fields.　So　far,　it　is　still　a　difficult　problem　to　synthesize　realistic　large-scale　crowd　rendering　with　an　interactive　frame-rate　in　the　real-time　applications.　Therefore,　efficiency　is　a　pivotal　problem　to　resolve.　This　paper　proposes　a　hybrid　approach　to　guide　crowd　movements　by　constructing　a　navigation　field　and　local　collision　avoidance　simultaneously.　Crowd　can　take　use　of　navigation　field　which　records　the　optimal　path　and　local　collision　test　keeping　them　off　obstacles　with　modified　vector　to　reach　their　desired　destinations.　With　our　proposed　method,　we　build　a　simulation　environment　for　crowd　evacuation　and　realized　the　evacuation　in　assembly　occupancies　successfully　with　excellent　rendering　result　and　high　efficiency　in　reasonable　frame.