Polymer　cover　windows　are　important　components　of　flexible　OLED　displays　but　they　easily　generate　wrinkles　because　of　their　weak　folding　resistance.　Increasing　the　polymer　thickness　can　improve　the　folding　resistance　but　it　decreases　the　touch　sensitivity.　Thus,　fabricating　highly　foldable　and　supersensitive　polymer　cover　windows　is　still　challenging.　Here,　by　incorporating　cellulose　nanocrystals　(CNCs)　and　zirconia　(ZrO2)　into　colorless　polyimide　(CPI),　we　developed　a　highly　foldable　and　supersensitive　hybrid　cover　window.　Inspired　by　the　theory　of　elasticity,　we　added　rigid　CNCs　into　CPI　to　improve　the　elastic　modulus　and　hence　the　foldability.　ZrO2　was　introduced　to　improve　dielectric　properties,　which　leads　to　improved　touch　sensitivity.　After　these　modifications,　the　elastic　modulus　of　the　cover　windows　was　increased　from　1432　to　2221　MPa,　whereas　its　dielectric　constant　was　increased　from　2.95　to　3.46　(@1　x　10(6)　Hz),　resulting　in　significantly　enhanced　foldability　and　sensitivity.　Meanwhile,　because　of　the　nano　size　of　CNCs　and　ZrO2,　the　hybrid　cover　windows　exhibit　excellent　optical　properties　with　the　transmittance　of　similar　to　88.1%@550　nm　and　haze　of　2.39%.　With　improved　and　balanced　mechanical,　dielectric,　and　optical　properties,　these　hybrid　cover　windows　overcome　current　cover　windows＇　defects　and　could　be　widely　used　in　next-generation　flexible　displays.