A　modified　floor　field　model　is　proposed　to　simulate　the　pedestrian　evacuation　behavior　in　a　room　with　multiple　exits.　The　modification　relies　upon　introduction　of　a　so-called　semidynamical　floor　field　which　additionally　embodies　two　cognition　coefficients　related　to　exit　width　and　pedestrian　distribution　around　exits.　The　energy　consumption　and　time　requirement　of　evacuees　are　numerically　investigated　and　the　Pareto　optimum　of　evacuation　efficiency　is　obtained　by　selecting　the　combinations　of　the　two　cognition　coefficients.　©　2017　Yan　Xu　et　al.