Metal-organic　polyhedra　(MOP),　as　a　new　type　of　molecule-based　porous　nanocage,　is　a　promising　material　in　membrane　separation.　However,　it　is　a　challenge　to　obtain　pure　MOP　membrane　to　take　full　advantage　of　its　nanocage.　In　this　study,　[Cu-24(5-tBu-1,3-BDC)(24)(S)(24)]　(MOP-tBu)　membranes　were　prepared　on　the　surface　of　ceramic　tubular　substrate　with　the　assistance　of　Co(OH)(2)　nano-array.　MOP-tBu　molecules　were　dynamic　pressure-　driven　assembled　into　the　confinement　space　of　vertically　arranged　Co(OH)(2)　nanosheets,　which　were　previously　formed　on　the　substrate　through　hydrothermal　synthesis.　With　this　strategy,　the　MOP-tBu　molecules　can　form　an　ultrathin　defect-free　separation　layer　on　the　surface　of　the　substrate.　Due　to　the　open　Cu2+　unsaturated　sites　(CUSs)　and　rich　benzene　rings　in　its　structure,　the　MOP-tBu　membrane　has　permselectivity　towards　the　aromatic　compounds.　In　addition,　the　MOP-tBu　membrane　is　endowed　with　high　permeability　because　of　its　large　cavity　and　small　apertures.　Therefore,　the　membranes　were　used　to　separate　aromatic/aliphatic　mixtures　through　pervaporation.　When　separating　50　wt%　toluene/n-heptane　mixtures,　the　permeate　flux　of　the　MOP-tBu　membrane　was　800　gm(-2)　h(-1)　with　the　separation　factor　of　5.4.　The　high　permeability　of　the　membrane　exhibited　great　potential　in　the　separation　of　aromatic/aliphatic　mixtures.