It　is　of　pivotal　significance　to　explore　robust　photocatalysts　to　promote　the　photoreduction　of　CO2　into　solar　fuels.　Herein,　an　intelligent　metal-insulator-semiconductor　(MIS)　nano-architectural　photosystem　was　constructed　by　electrostatic　self-assembly　between　cetyltrimethylammonium　bromide　(CTAB)　insulator-capped　metal　Ni　nanoparticles　(NPs)　and　covalent　triazine-based　frameworks　(CTF-1).　The　metal-insulator-CTF　composites　unveiled　a　substantially　higher　CO　evolution　rate　(1254.15　μmol　g−1　h−1)　compared　with　primitive　CTF-1　(1.08　μmol　g−1　h−1)　and　reached　considerable　selectivity　(98.9　%)　under　visible-light　irradiation.　The　superior　photocatalytic　CO2　conversion　activity　over　Ni-CTAB-CTF　nanoarchitecture　could　be　attributed　to　the　larger　surface　area,　reinforced　visible-light　response,　and　CO2　capture　capacity.　More　importantly,　the　Ni-CTAB-CTF　nanoarchitecture　endowed　the　photoexcited　electrons　on　CTF-1　with　the　ability　to　tunnel　across　the　thin　CTAB　insulating　layer,　directionally　migrating　to　Ni　NPs　and　thereby　leading　to　the　efficient　separation　of　photogenerated　electrons　and　holes　in　the　photosystem.　In　addition,　isotope-labeled　(13CO2)　tracer　results　verified　that　the　reduction　products　come　from　CO2　rather　than　the　decomposition　of　the　photocatalysts.　This　study　opens　a　new　avenue　for　establishing　a　highly　efficient　and　selective　artificial　photosystem　for　CO2　conversion.　©　2022　Wiley-VCH　GmbH.