The　photocatalytic　two-electron　O-2　reduction　reaction　(2e(-)　ORR)　for　high-value　hydrogen　peroxide　(H2O2)　production　is　attracting　widespread　attention　as　a　green　and　promising　research　pathway.　Despite　multiple　optimization　strategies,　the　current　2e(-)　ORR　systems　remain　constrained　by　photogenerated　carrier　recombination　and　slow　O-2　reduction　kinetics.　Therefore,　a　refined　photocatalyst　design　is　urgently　needed　to　overcome　these　constraints,　enabling　enhanced　H2O2　activity　and　deeper　exploration　of　reaction　mechanisms.　Here,　we　design　surface　defect　sites　(N　vacancies)　and　oxygen-affine　CoOx　nanoclusters　on　polymeric　carbon　nitride　(CN)　to　break　through　the　above　limitations　for　enhanced　photocatalytic　H2O2　production.　The　introduction　of　N　vacancies　significantly　enhances　the　photogenerated　carrier　separation,　and　highly　active　CoOx　nanoclusters　optimize　the　surface　reaction　process　from　O-2　to　H2O2,　synergistically　improving　the　activity　and　selectivity　of　H2O2　production.　The　designed　photocatalyst　(CoOx-NvCN)　achieves　a　H2O2　production　rate　of　244.8　mu　mol　L-1　h(-1)　in　pure　water,　with　an　apparent　quantum　yield　(AQY)　of　5.73%　at　420　nm　and　a　solar-to-chemical　energy　conversion　(SCC)　efficiency　of　0.47%,　surpassing　previously　reported　CN-based　photocatalysts.　Importantly,　experiments　and　theoretical　calculations　reveal　that　N　vacancies　optimize　the　photoelectronic　response　characteristics　of　the　CN　substrate,　while　the　CoOx　nanoclusters　promote　O-2　adsorption　and　activation,　reducing　the　formation　energy　barrier　for　crucial　intermediate　*OOH,　thereby　accelerating　H2O2　generation.　This　work　provides　a　feasible　approach　to　the　photocatalyst　design　strategy　that　simultaneously　facilitates　photogenerated　carrier　separation　and　effective　active　sites　for　high-performance　H2O2　production.