Pervaporation　has　shown　great　promise　in　recovering　alcohol　from　fermentation　broth.　However,　the　separation　performance　determined　by　membrane　material　and　structure　should　be　further　improved.　In　this　study,　polyhedral　oligomeric　silsesquioxane　(POSS)　nanocage　was　used　as　nanofillers　to　provide　preferential　pathways　for　ethanol　molecules　in　polydimethylsiloxane　(PDMS)　membrane.　To　improve　dispersion　of　POSS　nanocages　in　PDMS　matrix,　the　POSS　were　anchored　on　the　graphene　oxide　(GO)　nanosheets.　At　the　meantime,　the　aggregation　of　GO　nanosheets　could　also　be　prevented　as　the　GO　surface　turned　to　be　hydrophobic　by　the　modification　of　POSS,　and　the　nanoporous　POSS　cage　could　reduce　interface　defects　between　GO　nanosheets　and　PDMS　matrix.　The　obtained　POSS-GO/PDMS　nanocomposite　membranes　exhibited　excellent　separation　performance　for　ethanol　permselectivity.　The　flux　could　reach　1346.9　g　m(-2)　h(-1)　with　a　separation　factor　of　11.2　when　recovery　of　ethanol　from　5　wt%　ethanol/water　mixture.　In　addition,　the　separation　performance　of　the　POSS-GO/PDMS　membrane　could　maintain　stability　in　120　h.　Therefore,　the　POSS　modified　GO　nanosheets　shown　great　potential　in　the　fabrication　of　ethanol　permselective　pervaporation　membranes.