Exploiting　emerging　artificial　photosystems　with　regulated　vectorial　charge　transfer　pathways　is　retarded　by　the　difficulties　in　precise　interface　modulation　at　the　nanoscale　level,　deficiency　of　suitable　assembly　methodologies,　and　ultra-short　charge　lifetime.　Herein,　it　is　first　conceptually　demonstrated　the　general　design　of　transition　metal　chalcogenides　quantum　dots　(TMCs　QDs)-insulating　polymer-metal　oxides　(MOs)　electron-tunneling　photosystems,　wherein　TMCs　QDs　are　controllably　layer-by-layer　self-assembled　on　the　MOs　substrates　assisted　by　an　ultrathin　insulating　polymer　interim　layer.　It　is　ascertained　that　electrons　photoexcited　over　TMCs　QDs　in　spatially　highly　ordered　MOs/(TMCs　QDs/polymer)n　multilayered　heterostructures　can　be　unidirectionally　extracted　and　tunneled　to　the　MOs　substrates　across　the　intermediate　insulating　polymer　layer　by　engendering　the　tandem　charge　transfer　to　accelerate　the　interfacial　charge　migration　kinetics,　thereby　triggering　the　significantly　boosted　net　efficiency　of　solar-driven　photoelectrochemical　water　oxidation.　This　study　would　spark　new　inspirations　for　designing　novel　electron-tunneling　photosystems　for　fine　carrier　modulation　towards　solar　energy　harvesting　and　conversion.　©　2021　Wiley-VCH　GmbH.