The　entry　of　Hg2+　into　the　human　body　can　lead　to　serious　damage　to　some　organs　and　it　is　vital　to　construct　some　simple　but　sensitive　Hg2+　assay　methods.　A　multicolor　sensor　for　Hg2+　was　constructed　depended　on　the　inhibition　of　peroxidase　activity　of　Fe/Co-MIL-88(NH2)　mediated　by　DNA　and　color　change　caused　by　the　etching　of　gold　nanobipyramids　(Au　NBPs).　The　enzymatic　activity　of　Fe/Co-MIL-88(NH2)　can　be　inhibited　by　adsorbing　the　T-rich　oligonucleotide　sequence　on　its　surface.　Hg2+　can　combine　with　thymine　of　the　T-rich　oligonucleotide　sequence　to　constitute　T-Hg2+-T　complex,　and　cause　the　transforming　of　T-rich　oligonucleotide　sequence　into　three-dimensional　structure　and　desorbed　from　Fe/Co-MIL-88(NH2)　surface.　Which　results　in　the　restoration　of　the　peroxidase　activity　of　Fe/Co-MIL-88(NH2),　and　then　it　catalyzes　the　3,3　&　PRIME;,5,5　&　PRIME;-tetramethylbenzidine　(TMB)　to　engender　TMB2+,　TMB2+　can　etch　Au　NBPs,　this　accompanied　with　a　peak　shift　of　the　UV-vis　spectrum　and　recognizable　color　changes　of　the　system.　Semi-quantitative　can　be　realized　using　the　multicolor　changes　of　the　Au　NBPs　as　the　reading　mode.　Furthermore,　quantitative　sensing　can　be　achieved　by　measuring　the　UV-vis　peak　shift　of　the　system.　The　linear　response　range　is　1.0　nM-10　&　mu;M,　and　the　detection　limit　(LOD)　is　0.28　nM.