Magic-sized　nanoclusters　(MSCs)　have　been　attracting　enduring　interest　by　virtue　of　the　quantum　confinement　effect,　discrete　energy　band　structure,　and　enriched　catalytic　active　sites.　Nevertheless,　up　to　date,　exploration　of　MSCs　artificial　photosystems　and　fine-tuning　of　spatial　vectorial　charge　transfer　in　photoredox　catalysis　have　so　far　been　scarcely　reported.　Hence,　we　employed　a　facile　and　easily　accessible　layer-by-layer　(LbL)　assembly　strategy　to　highly　ordered,　alternately,　and　periodically　deposit　oppositely　charged　tailor-made　transition　metal　chalcogenides　(TMCs)　MSCs　and　non-conjugated　polymer　(NCP)　building　blocks　on　the　MO　substrate,　resulting　in　the　MO/(NCP-TMCs　MSCs)n　multilayer　heterostructures.　It　is　affirmed　that　the　ultra-thin　NCP　uniformly　intercalated　at　the　interface　of　every　TMCs　MSCs　layer　fosters　the　unidirectional　electron　flow　from　TMCs　MSCs　to　MO　substrate　with　the　assistance　of　NCP,　and　moreover　the　multilayered　interface　configuration　benefits　the　establishment　of　cascade　tandem　charge　transfer　route,　synergistically　giving　rise　to　the　significantly　enhanced　charge　separation　and　boosted　solar　water　oxidation　performances　of　MO/(TMCs　MSCs-NCP)n　heterostructure　under　simulated　solar　light　irradiation.　Our　work　elucidates　the　specific　roles　of　NCP　and　MSCs　as　charge　relay　mediators　and　photosensitizers,　affording　a　quintessential　paradigm　to　rationally　regulate　the　photocarrier　transport　and　separation　over　MSCs　for　solar　energy　conversion.　©　2025　Wiley-VCH　GmbH.