Photoresponsive　luminescent　materials　(PLMs)　have　attracted　much　attention　in　various　optoelectronic　fields,　especially　in　optical　data　storage.　Multi-wavelength　(N-wavelength)　based　optical　storage　is　a　promising　approach　to　increase　the　data　storage　density,　but　its　current　application　is　limited　by　the　fact　that　most　PLMs　have　only　two-wavelength　emissive　states　after　certain　light　excitation,　which　requires　simultaneous　use　of　several　PLMs　and　different　irradiation　light　sources.　In　this　study,　we　discovered　that　the　wavelength　of　perovskite　nanocrystals　(PNCs)　in　the　presence　of　dichloromethane　(DCM)　could　be　continuously　and　precisely　tuned　over　a　very　wide　color　range　(from　red　to　violet)　with　the　help　of　a　single　UV　light　source.　The　changes　in　crystal　structures　and　optical　properties　of　PNCs　during　UV　irradiation　were　investigated　in　detail;　the　effects　of　capping　ligand,　solvent,　UV　irradiation　power　and　time　were　evaluated,　and　the　mechanism　of　UV　triggered　PNC　fluorescence　change　was　studied　and　is　discussed.　Finally,　the　applicability　of　PNCs/DCM　film　in　N-wavelength-based　high-density　optical　data　storage　was　verified.　©　2022　The　Royal　Society　of　Chemistry.