The　sensitive　detection　of　glutathione　(GSH)　level　is　of　great　significance　to　disease　diagnosis.　However,　commonly　used　fluorometry　method　usually　suffers　from　limited　sensitivity,　potential　interferences　and　inefficient　detection.　In　this　work,　a　smartphone-assisted　and　perovskite-based　sensing　platform　for　dual-readout　detection　of　GSH　was　developed:　the　silica　coated　perovskite　quantum　dots　(PQD@SiO2)　with　a　single　particle　level　and　high　fluorescence　efficiency　were　employed　as　fluorophore,　which　greatly　avoids　aggregation-caused　quenching　effect　caused　by　multi-particles　embedded　in　one　SiO2　shell,　and　the　manganese　dioxide　(MnO2)　nanosheets　were　used　as　quencher.　With　the　addition　of　GSH,　the　fluorescence　intensity　of　PQD@SiO2-MnO2　composites　gradually　enhances,　while　the　color　of　solution　turns　from　dark　brown　to　light　yellow　under　sunlight,　which　enables　the　dual-signal　(fluorescence　and　colorimetric)　and　reliable　detection　of　GSH　level.　In　addition,　the　introduction　of　smartphones　integrated　image　recording　and　data　processing,　further　promotes　the　simple,　visualized,　cost-effective　and　real-time　determination　of　GSH.　The　synthesis　of　PQD@SiO2　at　a　single　particle　level,　as　well　as　the　strategies　of　dual-mode　and　smartphone-assisted　detection,　holds　the　promising　prospect　in　biosensing　and　chemical　sensing.