In　this　paper,　to　solve　the　problem　of　LED　heat　dissipation,　a　integrated　flat　plate　heat　pipe　was　designed　and　the　thermal　performance　was　analyzed.　An　experimental　rig　was　built　to　test　the　performance　of　the　flat　plate　heat　pipe.　Project　was　designed　to　make　sure　the　simulated　heat　source　was　insulated　well.　The　simulated　heater　was　fabricated　to　provide　the　heat　flux　which　was　needed　in　the　experiment.　By　analyzing　uncertainty　of　measurement,　the　results　show　that　uncertainty　of　measurement　is　in　the　reasonable　range.　The　influence　of　the　heat　power,　filling　ratio,　and　working　fluid　on　the　thermal　performance　of　the　flat　plate　heat　pipe　was　studied.　The　experimental　results　show　that　the　flat　heat　pipe　has　good　temperature　uniformity.　The　higher　the　power　is,　the　lower　the　vapor　chamber　thermal　resistance　is.　The　optimal　filling　ratio　of　the　flat　heat　pipe　is　40%　in　the　research.　Among　the　three　tested　working　fluids,　the　heat　transfer　performance　of　water　proves　to　be　the　best.　©,　2015,　Beijing　University　of　Technology.　All　right　reserved.