In　cases　of　liver　lesions　or　metabolic　blockages,　the　accumulation　of　bilirubin　in　the　blood　can　lead　to　hyperbilirubinemia,　resulting　in　jaundice.　Hence,　the　development　of　a　rapid　and　highly　selective　assay　strategy　for　accurately　quantifying　free　bilirubin　concentrations　in　humans　is　crucial　for　clinical　diagnosis　and　treatment.　In　this　study,　a　postsynthetic　modification　(PSM)　strategy　was　used　to　obtain　UiO-66-PSM　(UP)　by　the　aldimine　condensation　reaction　of　metal-organic　framework　UiO-66-NH　2　with　2,3,4-trihydroxybenzaldehyde.　UP　itself　possesses　strong　fluorescent　properties.　Subsequently,　UiO-66-PSM-Fe　(UPF)　was　synthesized　by　incorporating　Fe　3　+　onto　the　UP　surface　using　a　one-pot　method,　where　the　interaction　of　Fe　3　+　with　UP　induced　fluorescence　quenching.　Bilirubin　has　a　strong　binding　affinity　for　Fe　3　+　.　Therefore,　it　can　react　with　the　UPF,　losing　Fe　3　+　and　regaining　fluorescence,　and　thus　realizing　the　detection　of　bilirubin.　In　order　to　further　improve　the　detection　outcome　and　facilitate　the　application,　UPF　was　loaded　onto　gelatin　methacryloyl　hydrogel　to　construct　a　fluorescence　sensor.　This　enabled　highly　sensitive　determination　of　bilirubin　with　a　method　limit　of　detection　of　5.67　pM.　Furthermore,　genuine　human　urine　samples　were　analyzed,　demonstrating　the　practical　application　of　the　assay　in　discovering　human　health　conditions　associated　with　bilirubin.