In　this　paper,　a　series　of　Cs3　Cu2　I5　perovskite　phosphors　modified　with　L-histidine　(L-His)　and　5-aminovaleric　(5-Ava)　acid　were　prepared　by　simple　room　temperature　ball　milling　method.　The　phase,　morphology,　optical　and　stability　properties　of　Cs3　Cu2　I5　∶　x%　L-His　and　Cs3　Cu2　I5　∶　x%　5-Ava(x　=　0,　0.　5,　1,　1.　5,　2)　perovskites　were　analyzed.　The　presence　of　amino　acids　does　not　change　the　crystal　structure　of　Cs3　Cu2　I5　perovskite,　which　still　belongs　to　the　Pnma　space　group.　However,　the　introduction　of　amino　acids　affects　the　grain　size　of　perovskite　and　effectively　improves　its　optoelectronic　properties.　When　x　=　1,　the　fluorescence　intensity　of　Cs3　Cu2　I5　perovskite　modified　with　L-His　and　5-Ava　increases　by　about　1.　30　and　1.　41　times　compared　with　that　of　pure　Cs3　Cu2　I5　perovskite,　and　the　photoluminescence　quantum　yield　(PLQY)　increases　by　25.　09　percentage　points　and　30.　47　percentage　points,　respectively.　The　fluorescence　lifetime　of　the　modified　perovskites　is　effectively　prolonged.　It　is　found　that　the　improvement　in　performance　may　be　related　to　the　function　of　amino　and　carboxyl　groups　in　amino　acids,　which　blunts　the　defects　of　perovskites　and　inhibits　energy　loss　in　non-radiative　recombination　processes.　In　addition,　the　blue　light-emitting　diode　(LED)　was　prepared　by　Cs3　Cu2　I5　perovskite　phosphor　modified　with　L-His　and　5-Ava　acid,　and　the　respective　light　efficiency　is　1.　85　and　2.　10　times　higher　than　that　of　pure　Cs3Cu2I5　device　under　biased　current　of　70　mA,　indicating　that　such　materials　have　great　application　value　in　the　LED　field.　©　2023　Chinese　Ceramic　Society.　All　rights　reserved.