Emerging　excessive　greenhouse　gas　emissions　pose　great　threats　to　the　ecosystem,　which　thus　requires　efficient　CO2　capture　to　mitigate　the　disastrous　issue.　In　this　report,　large　molecular　size　bisphenol　A　ethoxylate　diacrylate　(BPA)　was　employed　to　crosslink　poly　(ethylene　glycol)　methyl　ether　acrylate　(PEGMEA)　via　the　green　and　rapid　UV　polymerization　strategy.　The　microstructure　of　such-prepared　membrane　could　be　conveniently　tailored　by　tuning　the　ratio　of　the　two　prepolymers,　aiming　at　obtaining　the　optimized　microstructures　with　suitable　mesh　size　and　PEO　sol　content,　which　was　approved　by　a　novel　low-field　nuclear　magnetic　resonance　technique.　The　optimum　membrane　overcomes　the　trade-off　challenge:　dense　microstructures　lower　the　gas　permeability　while　loose　microstructures　lower　high-pressure-resistance　capacity,　realizing　a　high　CO2　permeability　of　1711　Barrer　and　100-h　long-term　running　stability　under　15　atm.　The　proposed　membrane　fabrication　approach,　hence,　opens　a　novel　gate　for　developing　high-performance　robust　membranes　for　CO2　capture.　©　2022　Institute　of　Process　Engineering,　Chinese　Academy　of　Sciences