Plasmonic　photocatalytic　degradation　and　photoelectrochemical　water　splitting　is　very　promising　in　the　process　of　ecological　environment　protection.　However,　the　efficiencies　reported　are　still　too　low　for　practical　application　due　to　the　high　recombination　of　photogenerated　electrons　and　holes,　which　can　be　improved　by　optimizing　the　design　and　assembly　of　highly　ordered　pore　structures.　In　our　work,　a　composite　plasmonic　metal/semiconductor　photocatalyst,　Au/ZnO　hybrid　inverse-opal　nanomaterial　(Au/ZnO-IO),　was　prepared　by　in-situ　grown　Au　nanoparticles　on　inner　and　outer　of　ZnO　framework.　The　3D　ordered　Au/ZnO-IO　photocatalyst　exhibited　excellent　photocatalytic　activity　in　bisphenol　A　degradation　and　photoelectrochemical　water　splitting.　The　improved　photoactivities　were　proved　to　be　caused　by　the　increased　light　absorption　and　special　charge　transfer　of　photogenerated　electrons,　which　significantly　restraint　the　recombination　rate　and　prolong　the　lifetime　of　photoexcited　carries.　Based　on　the　analysis　of　active　species　experiments,　photoelectrochemical　measurements,　energy　level　of　schottky　junction　and　finite-difference　time-domain　(FDTD)　simulations,　the　degradation　mechanism　on　Au/ZnO-IO　nanocomposite　was　supposed.　This　work　provides　insights　into　the　charge　transfer　regulation　by　constructing　the　3D　plasmonic　metal/semiconductor　inverse-opal　photocatalyst　and　may　serve　as　a　promising　strategy　for　photocatalytic　degradation　of　organic　pollutants　and　water　splitting.