According　to　the　hydration　size　and　charge　property　of　separated　ions,　the　transport　channel　can　be　constructed　to　achieve　precision　ion　separation,　but　the　ion　geometry　as　a　separation　parameter　to　design　the　channel　structure　is　rarely　reported.　Herein,　a　reverse-selective　anion　separation　membrane　composed　of　a　metal-organic　frameworks　(MOFs)　layer　with　a　charged　“hourglass”　channel　as　an　ion-selective　switch　to　manipulate　oxoanion　transport　is　developed.　The　gate　in　“hourglass”　with　tetrahedral　geometry　similar　to　the　oxoanion　(such　as　SO2-　4,　Cr　2O2-　7,　and　MnO-　4)　boosts　the　transmission　effect　oxoanion　much　larger　than　Cl−　through　geometric　matching　and　Coulomb　interaction.　Specific　channel　structure　exhibits　an　abnormal　selectivity　for　SO2-　4/Cl−　of　20,　Cr　2O2-　7/Cl−　of　6.6,　and　MnO-　4/Cl−　of　4.0　in　a　binary-ion　system.　The　transfer　behavior　of　SO2-　4　in　the　channel　revealed　by　molecular　dynamics　simulation　and　density　functional　theory　calculation　further　indicates　the　mechanism　of　the　abnormal　separation　performance.　The　universality　of　the　membrane　structure　is　validated　by　the　formation　of　different　nitrogen-containing　modified　layers,　which　also　achieves　in　situ　growth　of　the　MOFs　layer,　and　exhibits　similar　reversal　separation　performance.　The　geometric　configuration　control　of　ion　transport　channels　presents　a　novel　effective　strategy　to　realize　the　precise　separation　of　target　ions.　©　2024　Wiley-VCH　GmbH.