First-principles　calculations　based　on　density-functional　theory　(DFT)　are　used　to　investigate　the　effect　of　H　on　the　elastic　properties　of　Al2Cu　in　this　study.　Calculations　of　elastic　properties　revealed　that　H　changes　the　mechanical　properties　of　Al2Cu　especially　in　ductile　and　brittle　characteristics,　and　H　atomic　concentration　may　leads　to　hydrogen　softening　and　hardening,　which　is　expected　to　change　the　properties　of　Al2Cu　by　hydrogen　treatment.　©　2021