The　advancement　of　pure-red　perovskite　light-emitting　diodes　(PeLEDs)　is　still　a　challenge　because　of　surface　＂wastes＂　(like　surface　vacancies　and　excessive　insulating　ligands)　on　quantum　dots　(QDs).　Herein,　we　develop　a　method　to　synthesize　single-halide　pure-red　CsPbI3　QDs,　combining　a　strong　quantum　confinement　effect　and　meticulous　surface-cleaning-induced　ligand　exchange.　We　achieve　pure-red　emitting　QDs　by　controlling　the　size　and　uniformity　under　iodide-rich　conditions.　Subsequently,　vacancy　defects　and　insulating　ligands　are　cleared　through　introducing　acid.　Then　this　surface-cleaning　process　induces　ligand　exchange　to　further　inhibit　the　nonradiative　recombination　and　improve　the　electrical　property　of　QDs.　These　QDs　show　a　pure-red　photoluminescence　(PL)　at　635　nm　with　the　PL　quantum　yield　(PLQY)　of　99%.　Finally,　PeLEDs,　which　utilize　these　QDs,　demonstrate　a　pure-red　electroluminescence　(EL)　peak　at　638　nm　with　a　maximum　external　quantum　efficiency　(EQE)　of　26.0%　and　an　excellent　half-lifetime　(T-50)　of　490　min　at　an　original　luminance　of　102　cd/m(2).