A proton-prompted ligand exchange strategy is introduced to enhance the performance of CsPbI₃ quantum dot light-emitting diodes (QLEDs). This method involves the in-situ exchange of short-chain 5-aminopentanoic acid (5AVA) ligands with long-chain oleic acid and oleylamine ligands during the cooling stage of QD synthesis. The strategy maintains the size and morphology of CsPbI₃ QDs while improving their optical properties and conductivity. The resulting QDs exhibit enhanced stability and photophysical properties, leading to a significant improvement in QLED performance. The external quantum efficiency of the QLEDs is increased from 18.63% to 24.45%, and the half-operational lifetime is improved by 70 times. The QLEDs emit at 645 nm with a record maximum external quantum efficiency of 24.45% and a stable electroluminescence. The 5AVA ligands effectively passivate surface defects, enhance charge transfer, and improve the overall performance of the QLEDs. The method provides a new approach for ligand exchange in small-size CsPbI₃ QDs, offering a promising solution for high-performance perovskite QLEDs.A proton-prompted ligand exchange strategy is introduced to enhance the performance of CsPbI₃ quantum dot light-emitting diodes (QLEDs). This method involves the in-situ exchange of short-chain 5-aminopentanoic acid (5AVA) ligands with long-chain oleic acid and oleylamine ligands during the cooling stage of QD synthesis. The strategy maintains the size and morphology of CsPbI₃ QDs while improving their optical properties and conductivity. The resulting QDs exhibit enhanced stability and photophysical properties, leading to a significant improvement in QLED performance. The external quantum efficiency of the QLEDs is increased from 18.63% to 24.45%, and the half-operational lifetime is improved by 70 times. The QLEDs emit at 645 nm with a record maximum external quantum efficiency of 24.45% and a stable electroluminescence. The 5AVA ligands effectively passivate surface defects, enhance charge transfer, and improve the overall performance of the QLEDs. The method provides a new approach for ligand exchange in small-size CsPbI₃ QDs, offering a promising solution for high-performance perovskite QLEDs.