Highly　effective　flexible　thin　film　encapsulation　(TFE)　is　significant　and　challenging　for　organic　light-emitting　diodes　(OLEDs).　In　this　work,　the　Al2O3　film　fabricated　by　the　atomic　layer　infiltration　(ALI)　technique　penetrates　into　the　PDMS　material　to　form　PDMS/Al2O3　hybrid　flexible　thin　films　for　OLED　encapsulation　to　prolong　its　lifetime.　It　was　found　that　the　penetrative　depth　and　density　of　Al2O3　in　PDMS　could　be　regulated　by　the　pulse　time　of　the　ALI　precursor　and　reached　saturation.　The　penetration　of　the　Al2O3　film　could　not　only　enhance　the　barrier　performance　of　PDMS/Al2O3　hybrid　films　but　also　alleviate　the　interfacial　stress　between　PDMS　and　Al2O3.　As　a　result,　3　pairs　of　PDMS/Al2O3　hybrid　films　with　a　water　vapor　transmission　rate　(WVTR)　of　9.24　×　10-5　g/m2/day　measured　at　25　°C/50%　RH　were　successfully　prepared.　The　hybrid　films　were　applied　as　encapsulation　layers　for　OLED　devices,　whose　brightness　remains　more　than　50%　of　the　initial　brightness,　exhibiting　great　barrier　properties.　Finally,　the　relationships　between　the　penetrative　degree,　inorganic　layer　thickness,　and　maximum　stress　of　PDMS/Al2O3　hybrid　flexible　films　under　different　bending　deformations　were　simulated　and　verified　by　the　experiment.　These　results　indicate　the　promising　application　of　PDMS/Al2O3　hybrid　films　prepared　by　ALI　in　OLED　encapsulation　and　stretchable,　wearable,　and　flexible　devices.　©　2023　American　Chemical　Society.