Membrane　technology,　as　an　efficient　and　eco-friendly　separation　means,　has　demonstrated　substantial　superiority　in　liquid-based　separation　and　plays　a　pivotal　role　in　environmental　conservation　and　resource　utilization.　Traditional　polymer-based　membranes　have　long　dominated　the　market　for　their　simple　preparation　and　low　cost.　But　the　disordered　structure　and　irregular　aperture　of　conventional　amorphous　membranes　seriously　hinder　their　performance.　Recently,　the　emergence　of　covalent　organic　frameworks　(COFs)　has　brought　new　vigor　to　membrane-based　separation.　COFs,　connected　by　covalent　bonds,　have　good　crystallization　and　regular　and　uniform　pore　structure,　thereby　showcasing　excellent　stability　and　separation　performance,　becoming　an　ideal　membrane　material.　In　this　paper,　the　synthesis　and　modification　of　COF-based　membranes　were　reviewed,　their　inherent　properties　were　also　introduced.　Besides,　their　applications　in　liquid-based　separation　were　elaborated.　Lastly,　the　challenges　and　focal　points　were　discussed,　aiming　at　offering　inspirations　for　the　development　of　COF-based　membranes.　©　2025　Elsevier　B.V.