A　simple　hydrothermal　technique　was　used　for　the　synthesis　of　a　ternary　ZnO-Ag-BiVO4　nanocomposite.　The　morphology,　structure　and　optical　performance　of　ZnO-Ag-BiVO4　were　analyzed　by　XPS,　TEM,　XRD,　FT-IR,　FESEM,　PL,　and　DRS.　The　sharp　peaks　of　ZnO-Ag-BiVO4　indicated　the　good　crystalline　nature　of　the　photocatalyst.　FE-SEM　images　depicted　the　hexagonal　structure　of　ZnO　and　the　plate-like　structure　of　BiVO4.　The　heterostructured　catalyst　Ag-ZnO-BiVO4　is　capable　of　reducing　20　ppm　of　Cr(VI)　from　potassium　dichromate　in　100　mL　aqueous　solution　to　97%　within　70　min　under　visible　light.　The　first-order　rate　constant　value　of　0.0371　min(-1)　and　a　97%　reduction　for　the　ZnO-Ag-BiVO4　catalyst　show　its　maximum　photoreduction　efficiency.　The　optimum　pH　for　effective　Cr(VI)　reduction　on　ZnO-Ag-BiVO4　is　5　and　it　is　steady　and　recyclable.　The　photo　generated　electron　acts　mainly　in　the　photocatalytic　reduction　of　hexavalent　chromium.　The　photocurrent　analysis　shows　that　the　ZnO-Ag-BiVO4　composite　material　can　enhance　the　photoexcited　charge　production,　separation　and　migration,　which　improved　the　photocatalytic　reduction　of　Cr(VI).　Proposed　Z-scheme　mechanism　of　ternary　ZnO-Ag-BiVO4　clearly　explains　the　electron-hole　separation　and　higher　efficiency　of　this　nanocomposite　in　the　photoreduction.　Superscript/Subscript　Available