Construction　of　composite　semiconductors　is　an　effective　solution　to　elevate　the　efficiency　of　photocatalysis　by　prolonging　lifetime　of　photogenerated　hole　and　electrons.　Herein,　a　heterojunction　structure　composite　BiVO4/Bi4Ti3O12　was　synthesized　via　a　facile　in　situ　hydrothermal　condition.　The　novel　composite　photocatalyst　has　excellent　photocatalytic　ability　to　reduce　CO2　with　H2O　into　CH3OH　and　CO.　The　BiVO4/10　%　Bi4Ti3O12　sample　shows　the　highest　yields　of　CH3OH　and　CO　up　to　16.6　and　13.29　mu　mol　g(-1)　h(-1),　which　was　12.39　and　5.68　times　higher　than　that　of　pure　BiVO4,　and　9.88　and　2.80　times　higher　than　that　of　pure　Bi4Ti3O12,　respectively.　Such　a　high　activity　is　attributed　to　the　type　II　heterojunction　structure　which　significantly　enhances　separation　of　photogenerated　carriers　and　promotes　collaboration　between　the　water　oxidation　on　the　Bi4Ti3O12　and　the　CO2　reduction　on　BiVO4.　The　photocatalytic　reaction　mechanism　of　CO2　on　the　composite　was　proposed　according　to　experiment　results.