Pervaporation　is　an　effective　technique　to　improve　the　conversion　of　acetic　acid　in　the　esterification　reaction　through　in　situ　removing　the　product　water.　In　this　study,　a　co-solvent　assisted　contra-diffusion　strategy　was　used　to　prepare　covalent　organic　framework　(COF)　pervaporation　membrane　on　the　polyacrylonitrile　porous　substrate.　Fatty　alcohol　was　used　as　the　co-solvent　in　the　organic　phase　to　tune　the　reaction　region.　Subsequently,　the　COFs　were　formed　in　the　sub-surface　of　the　substrate　to　form　a　nanoconfined　composite　membrane,　which　was　then　modified　by　polyvinyl　alcohol　through　spinning　coating.　The　obtained　COF　composite　membranes　were　used　to　in　situ　remove　water　during　the　esterification　from　acetic　acid　and　ethanol.　Consequently,　compared　with　the　esterification　without　pervaporation,　the　conversion　of　acetic　acid　was　enhanced　from　74%　to　90%,　which　exhibited　an　excellent　intensification　for　the　esterification　reaction.