Considering　the　importance　of　C2H2in　industry,　it　is　of　great　significance　to　develop　porous　materials　for　efficient　C2H2/CO2separation.　Besides　the　high　selectivity,　the　C2H2adsorption　capacity　is　another　vital　factor　in　C2H2/CO2separation.　However,　the　＇trade-off＇　between　these　two　factors　is　still　perplexing.　Rational　pore　design　of　metal-organic　frameworks　(MOFs)　has　been　proven　to　be　an　effective　way　to　solve　the　above　problem.　In　this　work,　we　have　appropriately　combined　three　kinds　of　strategies　in　the　design　of　the　MOF　(FJI-H33),　i.e.,　the　introduction　of　open　metal　sites,　construction　of　cage-like　cavities,　and　adjustment　of　moderate　pore　size.　As　anticipated,　FJI-H33　exhibits　both　outstanding　C2H2adsorption　capacity　and　high　C2H2/CO2selectivity.　At　298　K　and　100　kPa,　the　C2H2storage　capacity　of　FJI-H33　is　154　cm3/g,　while　the　CO2uptake　is　only　80　cm3/g.　The　ideal　adsorbed　solution　theory　(IAST)　selectivity　of　C2H2/CO2(50:50)　is　calculated　as　high　as　15.5　at　298　K.　More　importantly,　the　excellent　practical　separation　performance　was　verified　by　breakthrough　experiments.　In　addition,　the　calculation　of　adsorption　sites　and　relevant　energy　by　density　functional　theory　(DFT)　provides　a　good　explanation　for　the　excellent　separation　performance　and　pore　design　strategy.　©　2022　American　Chemical　Society.　All　rights　reserved.