The　efficiency　of　photocatalytic　overall　water　splitting　was　mainly　limited　by　the　slow　reaction　kinetics　of　water　oxidation.　How　to　design　effective　surface　active　site　to　overcome　the　slow　water　oxidation　reaction　was　a　major　challenge.　Here,　we　propose　a　strategy　to　accelerate　surface　water　oxidation　through　the　fabrication　spatially　separated　double　active　sites.　FeCoPi/Bi4NbO8Cl-OVs　photocatalyst　with　spatially　separated　double　active　site　was　prepared　by　hydrogen　reduction　photoanode　deposition　method.　Due　to　the　high　matching　of　the　spatial　loading　positions　of　FeCoPi　and　OVs　with　the　photogenerated　charge　distribution　of　Bi4NbO8Cl　and　corresponding　reaction　mechanisms　of　substrate,　the　FeCoPi　and　OVs　on　the　(001)　and　(010)　crystal　planes　of　Bi4NbO8Cl　photocatalyst　provided　surface　active　site　for　water　oxidation　reaction　and　electron　shuttle　reaction　(Fe3+/Fe2+),　respectively.　Under　visible　light　irradiation,　the　evolution　O2　rate　of　FeCoPi/Bi4NbO8Cl　OVs　was　16.8　μmol　h−1,　as　32.9　times　as　Bi4NbO8Cl.　Furthermore,　a　hydrogen　evolution　co-catalyst　PtRu@Cr2O3　was　prepared　by　sequential　photodeposition　method.　Due　to　the　introduction　of　Ru,　the　Schottky　barrier　between　PbTiO3　and　Pt　was　effectively　reduced,　which　promoted　the　transfer　of　photogenerated　electrons　to　PtRu@Cr2O3　thermodynamically,　the　evolution　H2　rate　on　PtRu@Cr2O3/PbTiO3　increased　to　664.8　times.　On　based　of　the　synchronous　enhancement　of　the　water　oxidation　performance　on　FeCoPi/Bi4NbO8Cl-OVs　and　water　reduction　performance　on　PtRu@Cr2O3/PbTiO3,　a　novel　Z　-　Scheme　photocatalytic　overall　water　splitting　system　(FeCoPi/Bi4NbO8Cl-OVs)　mediated　by　Fe3+/Fe2+　had　successfully　constructed.　Under　visible　light　irradiation,　the　evolution　rates　of　H2　and　O2　were　2.5　and　1.3　μmol　h−1,　respectively.　This　work　can　provide　some　reference　for　the　design　of　active　site　and　the　controllable　synthesis　of　OVs　spatial　position.　On　the　other　hand,　the　hydrogen　evolution　co　catalyst　(PtRu@Cr2O3)　and　the　co　catalyst　FeCoPi　for　oxygen　evolution　contributed　to　the　construction　of　an　overall　water　splitting　system.　©　2023