Porous　aromatic　frameworks　(PAFs),　possessing　a　high　specific　surface　area,　inherent　porosity,　nanosized　channels　and　diverse　structure,　exhibit　extraordinary　potential　in　various　fields.　Herein,　PAF-56　membranes　were　in　situ　fabricated　on　modified　polyvinylidene　fluoride　(PVDF)　membranes　by　a　mild　and　facile　refluxing　method　(62　degrees　C)　and　applied　in　nanofiltration.　The　influence　of　reaction　time,　reactant　concentrations　and　catalyst　concentration　on　the　PAF-56/PVDF　membranes　were　explored.　The　PAF-56/PVDF　membranes　showed　a　remarkable　rejection　(＞95.08　%)　and　permeability　(＞40　L　m(-2)h(-1)　bar(-1))　for　dyes　(Mw　＞　319)　solutions.　The　membrane　also　exhibited　excellent　reusability　and　chemical　stability,　indicating　great　potential　for　actual　separations.