Intrinsic　and　surface　defects　are　the　crucial　factors　that　affect　the　stability　and　luminescence　efficiency　of　nanocrystals　(NCs).　Ion-doping　and　surface　passivation　are　considered　as　the　most　effective　strategies　to　suppress　the　intrinsic　and　surface　defects　of　NCs,　respectively.　Herein,　an　efficient　and　facile　double　passivation　process,　simultaneously　realizes　ion-doping　and　surface　passivation,　for　Cs3Cu2X5　(X=Cl,　Br　and　I)　NCs　is　developed　by　using　potassium　oleate　(K-OA)　as　passivator.　K　ion　is　used　as　ion-doping　passivation　and　OA　ion　is　used　as　the　organic　ligand　for　surface　passivation　of　NCs.　Compared　to　the　free　passivated　NCs,　the　Photoluminescence　quantum　yield　(PLQYs)　of　dual-passivated　Cs3Cu2X5　(X=Cl,　Br　and　I)　NCs　increase　significantly　from　2.87%,　11.6%　and　49.4-31%,　69.9%,　and　97.2%,　respectively.　Moreover,　the　stability　of　proposed　NCs　is　greatly　improved　(Cs3Cu2Cl5　NCs　maintain　63%　of　PL　efficiency　after　100　h,　Cs(3)Cu(2)Br(5　)and　Cs3Cu2I5　NCs　maintain　65%　and　97%　of　PL　efficiency　after　100　days,　respectively)　at　50-86%　relative　humidity　and　room　temperature　under　ambient　atmosphere.　(C)　2022　Published　by　Elsevier　B.V.