The　rapid,　portable,　and　in　situmeasurement　of　the　ascorbic　acid(AA)　solution　remains　a　challenge,　and　there　is　no　suitable　way　toachieve　multiscale　regulation　of　the　measurement　range　and　sensitivity.In　this　work,　water-soluble　CdTe,　CdTe/CdSe,　and　CdTe/CdSe/ZnS　quantumdots　(QDs)　were　used　as　fluorescence　probes　(FPs),　and　the　specificsensitivity　of　photoluminescence　(PL)　intensity　and　AA　were　used　asa　detection　indicator.　By　changing　the　concentration　of　the　FP　andthe　type　of　core-shell　structure,　multiscale　regulation　ofthe　measurement　range　and　sensitivity　was　realized.　The　same　FP　withdistinct　sensitivity　in　different　measurement　ranges　is　ingeniouslyrealized　by　double-layer　core-shell　CdTe/CdSe/ZnS　with　typeII-I　band　gap　transition,　which　greatly　expanded　the　application　fields.The　maximum　measurement　range　was　0-27　&　mu;M　and　the　minimumdetection　limit　was　0.014　&　mu;M　for　three　FP　systems.　The　capillarysensor　with　a　honeycomb　QD　film　attached　to　the　inner　wall　was　preparedby　drying　at　room　temperature,　high-temperature　heating,　and　laserprocessing,　which　greatly　increased　the　contact　area　between　the　QDsand　AA　and　reduced　the　measurement　time.　Furthermore,　the　microfluidicsystem　was　used　to　precisely　control　the　deposition　area　and　positionof　the　film,　the　concentration　of　the　FP　was　adjusted　and　the　depositionstatus　of　the　film　was　observed　in　real　time,　so　as　to　achieve　real-timein　situ　rapid　detection　of　the　four　concentration　orders　of　the　AAsolution.　This　work　is　of　great　significance　for　the　rapid,　portable,multifield,　and　in　situ　real-time　detection　in　the　field　of　biomoleculedetection.