The　zinc(II)　bis-(8-hydroxyquinoline)　(Znq2)　has　excellent　photoluminescence　properties,　and　its　fluorescence　emission　can　be　significantly　quenched　by　Fe3+　in　water.　To　accelerate　the　detection　response　of　Znq2　to　Fe3+,　a　luminescent　metal–organic　framework　Znq2@ZIF-8　based　on　guest　molecular　luminescence　was　constructed　by　growing　zeolite　imidazolate　framework-8　(ZIF-8)　on　the　outer　surface　of　Znq2.　The　results　show　that　the　prepared　Znq2@ZIF-8　has　an　octahedral　core–shell　structure,　a　particle　size　of　approximately　1–3　μm,　an　enhanced　specific　surface　area　of　1105.41　m2　g−1,　and　with　a　stable　green　luminescence　at　495　nm.　A　fluorescence　analytical　method　was　developed　for　the　detection　of　Fe3+　in　water,　the　correlation　coefficients　were　significant　in　the　Fe3+　concentration　range　of　0–600　μmol　L−1,　and　the　limit　of　detection　was　as　low　as　3.89　μmol　L−1.　The　spiked　recoveries　of　tap　water　samples　demonstrated　that　the　method　could　be　applied　to　practical　applications.　The　mechanism　of　fluorescence　detection　is　that　Fe3+　participates　in　the　competitive　coordination　of　Znq2@ZIF-8　metal　centers,　leading　to　the　collapse　of　the　crystal　structure,　meanwhile,　Fe3+　produces　a　certain　degree　of　competitive　absorption　of　the　excitation　light　of　Znq2@ZIF-8.　This　method　was　applied　for　the　detection　of　Fe3+　in　water　with　good　selectivity,　anti-interference　ability,　and　has　the　potential　to　be　used　as　a　rapid　detection　method.　©　The　Author(s)　2024.