There　are　usually　multiple　functional　spaces　that　meet　different　usage　needs　on　each　building　floor.　The　number　of　people　in　different　functional　spaces　varies,　resulting　in　an　uneven　distribution　of　people　on　each　floors.　When　the　building　is　subject　to　hazards,　users　inside　buildings　usually　evacuate　to　safe　areas　through　safety　exits.　Obviously,　when　the　exit　location　is　close　to　the　crowded　area,　more　people　can　be　evacuated　as　quickly　as　possible.　However,　existing　methods　for　optimizing　exit　locations　of　buildings　mainly　by　shortening　evacuation　paths　with　limited　considerations　of　the　dynamic　distributions　of　evacuees.　Since　the　ontology　has　semantic　description　capability　and　reasonability.　Therefore,　the　ontology　is　used　to　organize　the　design　information　related　to　the　optimization　of　exit　locations.　The　rules　are　further　set　to　reason　about　the　distribution　of　evacuees　and　the　optimal　exit　location.　Therefore,　a　design　optimization　method　for　exit　locations　based　on　BIM　and　ontology　is　proposed.　Firstly,　the　ontology　is　developed　to　describe　the　information　needed　for　design　optimization.　Then,　the　plan　layout　information　is　extracted　from　BIM　as　ontology　instances.　Next,　based　on　the　evacuation　simulations,　the　exit　location　optimization　strategies　were　created　for　the　different　distribution　of　evacuees,　and　the　strategies　were　translated　into　SWRL　rules.　Finally,　the　ontology　instance　and　SWRL　rules　are　combined　to　reason　about　the　exit　location　optimization　strategies　for　specific　projects.　Therefore,　this　study　provided　the　exit　location　optimization　strategies　to　make　the　evacuation　time　shorter　by　considering　the　distribution　of　evacuees.　The　automation　of　exit　location　reasoning　is　further　enhanced　by　using　the　constructed　ontology　to　organize　the　design　information　and　by　transforming　the　optimization　strategies　into　SWRL　rules.　The　feasibility　of　the　method　was　verified　using　several　cases.　By　comparing　the　evacuation　time　of　people　under　the　exit　location　recommended　by　this　method　and　the　exit　location　designed　by　the　shortest　evacuation　path,　it　is　concluded　that　the　method　proposed　in　this　paper　takes　into　account　the　distribution　of　people　in　the　plane　and　the　evacuation　time　is　shorter.