Tourists＇　crowding　perception　and　adjustment　behavior　under　crowded　condition　were　explored　and　the　influence　mechanism　of　tourists＇　crowding-adjustment　behavior　on　tour　routes　design　was　analyzed　to　enhance　the　tourists＇　experience　and　service　level　of　scenic　site.　＂Hot　link＂　was　defined　and　the　diversity　of　tour　routes　was　analyzed　according　to　the　popularity　and　sorting　location　of　＂Hot　link＂.　Tour　routes　multi-objective　optimization　functions　were　prompted　for　the　tour　route　design　regarding　the　maximum　satisfaction　and　the　minimum　walking　time　between　scenic　spots　and　the　minimum　crowding　degree　as　the　optimal　objectives.　Considering　the　number　of　visiting　scenic　spots,　visiting　time　and　other　constraint　conditions,　the　goodness　value　of　the　tour　route　was　calculated　based　on　the　particle　swarm　optimization　model.　The　impacts　of　weighed　coefficient　of　crowding　degree　of　scenic　spots　on　tour　routes　optimization　were　discussed.　A　questionnaire　of　tourists＇　tour　route　and　behavior　information　was　carried　out　in　the　Summer　Palace　and　the　optimal　tour　routes　were　listed　and　categorized.　Results　show　that　adjustment　behaviors　such　as　cognitive　adjustment,　behavior　adjustment　and　cease　adjustment　are　adaptive　to　improving　tour　experience　when　tourist　perceive　crowded.　The　＂Hot　link＂　number　of　quick　tour　and　depth　tour　is　1-2　and　2-3　respectively.　The　goodness　value　of　depth　tour　route　(No.75)　is　57.39　and　is　bigger　than　official　recommended　tour　route,　which　indicates　the　optimization　model　has　a　higher　accuracy.　The　number,　popularity,　sorting　location　and　crowding　degree　value　of　＂Hot　link＂　affect　tour　routes＇　goodness　value.　With　the　increase　of　weighed　coefficient　of　crowding　degree　of　scenic　spots,　some　tour　routes＇　goodness　value　increases,　and　the　recommended　sorting　changes.　©　2018,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.