In　order　to　solve　phase　change　energy-saving　technology　applications　in　building　envelope　thermal　design　and　improve　indoor　thermal　comfort,　experimental　and　theoretical　studies　about　phase　change　component　were　carried　out　in　this　paper.　The　composite　phase　change　component　with　different　mass　of　phase　change　material　was　made　of　super-hemihydrate　plaster　and　paraffin　phase　change　material.　DSC　method　was　used　to　test　phase　change　energy　storage　gypsum　board＇s　phase　change　temperature　and　phase　change　latent　heat　and　steady-state　test　method　was　used　to　test　thermal　conductivity　of　different　proportions　of　the　component.　Phase　change　heat　transfer　model　was　established　and　simplified.　Heat　transfer　process　and　heat　transfer　mechanism　of　the　component　were　analyzed.　Solved　by　numerical　simulation　to　study　the　effect　of　different　proportions　of　phase　change　component　in　the　Beijing　area.　Changing　thermal　conductivity　and　convective　heat　transfer　coefficient　respectively,　application　effects　were　studied　for　optimization.　The　results　show　that　along　with　the　rising　of　the　paraffin　content,　the　thermal　conductivity　of　phase　change　component　minished.　Among　the　four　kinds　ratio,　component　with　33%　PCM　had　the　best　application　effect　in　passive　buildings　in　Beijing　and　in　transition　season　its　energy-saving　amount　was　10%　more　than　that　in　traditional　buildings.　Enlarging　thermal　conductivity　and　convective　heat　transfer　coefficient　of　phase　change　component　can　both　improve　indoor　comfort　and　reduce　energy　consumption.　The　results　of　the　research　can　provide　a　reference　for　building　envelope　thermal　design　with　phase　change　material.　©　All　Rights　Reserved.