High-quality　backlit　display　puts　forward　urgent　demand　for　color-converting　materials.　Recently,　metal　halide　perovskites　(MHPs)　with　full　spectral　tunability,　high　photoluminescence　quantum　yields　(PLQYs),　and　high　color　purity　have　found　potential　application　in　wide-color-gamut　display.　Regrettably,　naked　MHPs　suffer　from　long-term　instable　issue　and　cannot　pass　harsh　stability　tests.　Herein,　amorphous-glass-protected　green/red　CsPbX3　quantum　dots　(QDs)　are　prepared　by　elaborately　optimizing　glass　structure,　perovskite　concentration,　and　in　situ　crystallization.　PLQYs　of　green　CsPbBr3@glass　and　red　CsPbBr1.5I1.5@glass　reach　94%　and　78%,　respectively,　which　are　the　highest　ones　of　CsPbX3@glass　composites　reported　so　far　and　comparable　to　colloidal　counterparts.　Benefited　from　complete　isolation　of　QDs　from　external　environment　by　glass　network,　CsPbX3@glass　can　endure　harsh　commercial　standard　aging　tests　of　85　degrees　C/85%RH　and　blue-light-irradiation,　which　are　applied　to　construct　white　light-emitting　diodes　(wLEDs)　with　high　external　quantum　efficiency　of　13.8%　and　ultra-high　luminance　of　500　000　cd　m(-2).　Accordingly,　the　perovskite　wLED　arrays-based　backlit　unit　and　a　prototype　display　device　are　designed　for　the　first　time,　showing　more　vivid　and　wide-color-gamut　feature　benefited　from　narrowband　emissions　of　CsPbX3　QDs.　This　work　highlights　practical　application　of　CsPbX3@glass　composite　as　an　efficient　and　stable　light　color　converter　in　backlit　display.