The　photocatalytic　overall　conversion　of　CO2　with　H2O　to　chemical　fuel　and　oxygen　mimicking　natural　photosynthesis　is　a　huge　challenge　in　photocatalysis.　This　work　shows　the　achievement　of　the　solar-driven　photo　catalytic　overall　CO2　reduction　with　H2O　to　CO　and　O-2　over　a　Persian　buttercup-like　BiOBrxCl1-x　solid　solution.　A　CO　generation　rate　of　15.86　mu　mol　g(-1)　h(-1)　with　the　approximate　stoichiometric　O-2　evolution　is　yielded　on　BiOBr0.6Cl0.4　solid　solution　under　simulated　solar　light　irradiation,　which　was　about　7.5　and　10.2　times　higher　than　that　of　pure　BiOCI　(2.11　mu　mol　g(-1)　h(-1))　and　BiOBr　(1.55　mu　mol　g(-1)　h(-1)),　respectively.　The　enhanced　photoactivity　is　contributed　to　the　mediate　band　gap　and　energy　level　tuned　by　the　formation　of　BioBr(x)Cl(1-x)　solid　solution　to　facilitate　the　separation　of　photogenerated　charges.　Besides　the　unique　electron　structure,　the　photoinduced　oxygen　vacancy　(O-v)　formed　on　BiOBrxCl1-x　solid　solution　also　plays　an　important　role　in　the　CO2　reduction.