The　Eu-doped　K0.5Na0.5NbO3pellucid　ceramics　were　first　preparedviaa　conventional　solid-state　reaction,　and　they　exhibited　light　illumination-induced　high-contrast　photochromism　of　both　optical　transmittance　and　photoluminescence　behaviors.　Through　thermal　treatment,　the　optical　performances　could　return　to　their　initial　states　and　displayed　excellent　reversibility.　Eu3+ions　were　selected　as　the　luminescent　activator　for　detecting　the　local　environment　of　the　K0.5Na0.5NbO3host.　Meanwhile,　the　effects　of　the　amount　of　Eu3+present　on　phase　structures,　microstructures,　optical　transmittance　and　photoluminescence　intensities　were　systematically　investigated.　The　results　suggest　that　Eu-doped　K0.5Na0.5NbO3transparent　ceramics　possess　multifunctionality　including　photochromism,　photoluminescence　and　optical　switching　properties,　and　that　they　exhibit　promising　potential　for　non-destructive　optical　data　storage　application.　©　The　Royal　Society　of　Chemistry　2021.