Solar-driven　CO2　conversion　to　high-value-added　chemical　fuels　has　been　deemed　as　an　emerging　way　of　alleviating　deteriorating　energy　depletion　and　greenhouse　effect.　Nevertheless,　precise　modulation　of　spatial　vectorial　charge　migration/separation　in　CO2　artificial　photosystem　remains　challenging　due　predominantly　to　the　ultrashort　charge　lifetime,　sluggish　charge　transfer　kinetics,　and　ultra-stable　symmetry　of　CO2　molecules,　rendering　stimulation　of　CO2　adsorption,　activation　and　reduction　a　grand　challenge.　Herein,　we　conceptually　demonstrate　the　design　of　a　novel　semiconductor-insulator-cocatalyst　charge　tunneling　photosystem　via　a　layer-by-layer　(LbL)　assembly　strategy,　which　involves　progressive　intercalation　of　dual　ultrathin　insulating　polymer　layers　in-between　layered　double　hydroxides　(LDHs)　and　transition　metal　chalcogenide　(TMC).　It　is　demonstrated　for　the　first　time　unleash　that　electron-hole　pairs　photoexcited　over　TMC　can　simultaneously　tunnel　through　the　insulating　polymer　interim　layers,　followed　by　holes　trapping　by　terminal　LDHs　and　directional　electrons　migration　to　the　CO2　molecules　absorbing　on　the　polymers　surface,　synergistically　boosting　the　charge　separation　and　reinforcing　the　solar　CO2　reduction.　This　work　would　open　a　shining　frontier　to　strategically　craft　novel　charge-tunneling　artificial　photosystems　and　benefit　the　fundamental　understanding　on　the　CO2　photoreduction　technology　toward　solar　energy　conversion.