Aiming　at　decision-making　for　correct　evacuation　route　and　considering　real-time　effect　of　indoor　fire　spread,　a　shortest　route　selection　model　is　proposed　on　the　basis　of　improved　ant　colony　algorithm.　Hexagonal　grid　map　is　employed　to　make　sure　of　a　constant　time　spent　moving　to　adjacent　grids　each　time,　so　the　spread　of　fire　and　evacuation　can　be　accomplished　at　the　same　time.　Parameters　of　fire　spread　are　obtained　by　using　the　fire　dynamics　simulator(FDS).　Then　the　real-time　effect　of　fire　spreading　on　the　evacuation　route　in　the　process　of　evacuation　is　analyzed.　Simulated　calculations　under　different　circumstances　illustrate　that　the　proposed　model　can　solve　the　problem　of＇moving　diagonally　through　the　wall＇　and　improve　the　accuracy　and　efficiency　of　evacuation,　thus　serving　as　guidance　for　the　research　on　intelligent　emergency　evacuation　system.　©　2018,　Editorial　Office　of　Control　and　Decision.　All　right　reserved.