The　development　of　high-performance　CO2　capture　membranes　is　an　urgent　requirement　to　combat　the　greenhouse　effect　and　climate　change.　Covalent　organic　frameworks　(COFs)　with　highly　ordered　porous　structure　and　modifiable　pore　environment　shows　substantial　potential　in　the　field　of　membrane　separation.　Nevertheless,　the　scarce　affinity　sites　and　large　pore　diameters　of　COFs　may　limit　their　effect　on　gas　separation　in　membranes.　In　the　present　work,　TPB-DMTP-COF　was　modified　with　imidazolium-based　ionic　liquid　[Emim][Tf2N]　(IL)　to　remedy　such　disadvantages　of　COFs　and　then　the　mixed　matrix　membranes　(MMMs)　were　prepared　by　introducing　IL@COF　into　PIM-1.　The　IL　modification　not　only　can　endow　the　TPB-DMTP-COF　with　better　CO2　affinity　and　narrowed　pore　size,　but　also　can　further　improved　interfacial　compatibility　among　PIM-1　and　TPB-DMTP-COF.　Therefore,　the　introduction　of　IL@COF　into　PIM-1　membrane　can　leads　to　an　increase　in　CO2/N2　separation　properties　of　the　obtained　membranes.　Notably,　3.0　wt%　IL@COF/PIM-1　MMMs　show　optimal　CO2　permeability　and　CO2/N2　selectivity　of　9137.7　Barrer　and　20.2,　respectively.　Such　high　separation　performance　exceeds　2008　Robeson　upper　bound.　Moreover,　the　resultant　MMMs　also　exhibit　favorable　continuous　operation　stability.　Overall,　the　combination　of　IL　and　COFs　may　provide　a　new　inspiration　for　designing　efficient　CO2　separation　MMMs.　©　2023　Elsevier　B.V.