In　this　work,　we　report　highly　flexible　QLEDs　based　on　a　quantum　dots-polymer　composite　emitting　layer.　Conventional　quantum　dot　films　exhibit　cracks　after　rough　bending.　Herein,　polymethyl　methacrylate　(PMMA)　was　doped　into　quantum　dot　solution,　acting　as　binder　for　neighboring　quantum　dots.　In　addition,　PMMA　can　be　serving　as　an　electron　blocking　layer　due　to　its　insulating　property,　and　then　balancing　the　charge　recombination　and　improving　device　performance.　The　flexible　QLEDs　have　excellent　mechanical　properties　with　an　ultimate　bend　radius　of　1.5　mm,　and　they　show　no　significant　performance　degradation　after　500　times　bending　with　radius　of　4　mm.　The　flexible　QLEDs　exhibit　high　performance　with　maximum　luminance　of　14880　cd/m2　and　maximum　current　efficiency　of　21.3　cd/A.　©　2019　Elsevier　Ltd