The　use　of　visible　light　to　initiate　one-pot　synergistic/cascade　reactions　is　a　green　and　energy　saving　strategy.　In　this　manuscript,　we　report　that　MIL-101(Fe)　can　act　as　a　multifunctional　catalyst　to　realize　the　oxidative　condensation　between　o-phenylenediamines　and　alcohols　to　synthesize　benzimidazoles　under　visible　light.　The　deposition　of　plasmonic　Au　nanoparticles　(Au　NPs)　on　MIL-101(Fe)　led　to　significantly　improved　activity.　Both　controlled　experiments　and　electron　spin　resonance　(ESR)　results　revealed　that　the　production　of　benzimidazoles　from　o-phenylenediamines　and　alcohols　involves　three　sequential　steps,　i.e.,　the　oxidative　dehydrogenation　of　alcohols　to　produce　aldehydes,　the　condensation　between　o-phenylenediamines　and　the　aldehydes　to　produce　Schiff　bases　and　their　oxidation　to　form　benzimidazoles,　via　a　superoxide　radical　(O-2(-))-mediated　pathway.　The　promoting　effect　of　plasmonic　Au　NPs　in　this　reaction　can　be　ascribed　to　the　effective　transfer　of　the　surface　plasmon　resonance　(SPR)-excited　hot　electrons　to　the　lowest　unoccupied　molecular　orbital　(LUMO)　of　MIL-101(Fe),　which　led　to　the　generation　of　more　active　O-2(-)　radicals.　This　study　not　only　provides　a　green　and　sustainable　way　for　the　synthesis　of　benzimidazoles,　but　also　highlights　the　great　potential　of　using　rationally　designed　plasmonic　metal　NP/MOF　nanocomposites　as　multifunctional　catalysts　for　light　initiated　one-pot　tandem/cascade　reactions.