Industrial　sewage　often　contain　metal　ions　and　dyes,　and　it　is　difficult　to　efficiently　remove　them　simultaneously.　In　this　work,　novel　ternary　MIL-53(Fe)/carbon　quantum　dots/noble　metal　(MIL-53(Fe)/CQDs/MNPs,　MNPs　=　Ag,　Pd,　Au)　nanocomposites　have　been　rationally　constructed　and　successfully　fabricated　by　a　facile　two-step　strategy　with　self-assembling　and　in-situ　photoreduction.　The　resulting　MIL-53(Fe)/CQDs/2%Au　composite　exhibits　excellent　photoactivity　for　the　Cr(VI)　reduction,　the　reduction　ratio　is　nearly　100%　after　20　min　of　visible　light　illumination.　The　rate　constant　of　MIL-53(Fe)/CQDs/2%Au　is　calculated　to　be　0.1820　min−1,　which　is　around　7.4,　2.76,　1.77　and　1.47　times　higher　than　that　of　as-prepared　MIL-53(Fe),　MIL-53(Fe)/CQDs,　MIL-53(Fe)/CQDs/2%Ag　and　MIL-53(Fe)/CQDs/2%Pd,　respectively.　More　significantly,　MIL-53(Fe)/CQDs/2%Au　nanocomposite　has　been　proven　to　serve　as　bifunctional　photocatalyst　for　simultaneously　removing　Cr(VI)/dye　mixed　system　pollutants.　The　superior　photoactivity　may　be　due　to　the　enhanced　light　absorption　intensity,　the　superior　electrical　conductivity　of　Au　and　CQDs,　as　well　as　surface　plasmon　resonance　(SPR)　effect　of　Au.　In　particular,　the　possible　photocatalytic　reaction　mechanism　has　been　carefully　investigated　and　proposed.　©　2020