In　this　study,　mesoporous　molecular　sieves　were　first　modified　by　silazanes,　and　then　doped　into　polydimethylsiloxane　(PDMS)　solution.　The　mixture　was　coated　on　polysulfone　membrane　to　obtain　organic-inorganic　hybrid　composite　membrane.　The　modified　mesoporous　molecular　sieves　were　characterized　by　BET　and　FT-IR.　The　results　of　BET　showed　that　pore　size　distribution　of　mesoporous　molecular　sieves　significantly　changed　before　and　after　modification.　It　could　be　observed　from　FT-IR　that　hydroxyl　peaks　of　the　mesoporous　molecular　sieve　decreased　and　even　disappeared　after　being　modified.　Simultaneously,　the　alkyl　characteristic　peaks　appeared.　The　surface　and　cross-section　morphologies　of　the　hybrid　composite　membrane　were　characterized　by　SEM.　The　effects　of　molecular　sieves　content,　feed　concentration　and　operation　temperature　on　the　pervaporation　performance　were　systematically　investigated.　Results　indicated　that　the　hydrophobic　of　mesoporous　molecular　sieves　modified　by　1,　1,　3,　3-Tetramethyldisilazane　obviously　increased.　The　modified　mesoporous　molecular　sieves/PDMS　hybrid　composite　membrane　had　an　excellent　performance　in　the　separation　of　alcohol/water　solution.　When　the　doping　amount　of　molecular　sieve　was　20%,　the　feed　concentration　was　3%,　separation　factor　of　the　hybrid　membrane　for　ethanol/water　mixture　was　9.8　with　the　permeation　flux　of　1　002　g/(m2·h),　and　separation　factor　of　the　n-butanol/water　mixture　could　reach　65.4　with　the　flux　of　1　402　g/(m2·h)　at　40　°C.