In　this　work,　the　H-2　dissociation　and　acetylene　hydrogenation　on　Cu　doped　CeO2(111)　were　studied　using　density　functional　theory　calculations.　The　results　indicated　that　Cu　doping　promotes　the　formation　of　oxygen　vacancy　(O-v)　which　creates　Cu/O　and　Ce/O　frustrated　Lewis　pairs　(FLPs).　With　the　help　of　Cu/O　FLP,　H-2　dissociation　can　firstly　proceed　via　a　heterolytic　mechanism　to　produce　Cu-H　and　O-H　by　overcoming　a　barrier　of　0.40　eV.　The　H　on　Cu　can　facilely　migrate　to　a　nearby　oxygen　to　form　another　O-H　species　with　a　barrier　of　0.43　eV.　The　rate-determining　barrier　is　lower　than　that　for　homolytic　dissociation　of　H-2　which　produces　two　O-H　species.　C2H2　hydrogenation　can　proceed　with　a　rate-determining　barrier　of　1.00　eV　at　the　presence　of　Cu-H　and　O-H　species.,　While　C2H2　can　be　catalyzed　by　two　O-H　groups　with　a　rate-determining　barrier　of　1.06　eV,　which　is　significantly　lower　than　that　(2.86　eV)　of　C2H2　hydrogenated　by　O-H　groups　on　the　bare　CeO2(111),　showing　the　high　activity　of　Cu　doped　CeO2(111)　for　acetylene　hydrogenation.　In　addition,　the　rate-determining　barrier　of　C2H4　further　hydrogenated　by　two　O-H　groups　is　1.53　eV,　much　higher　than　its　desorption　energy　(0.72　eV),　suggesting　the　high　selectivity　of　Cu　doped　CeO2(111)　for　C2H2　partial　hydrogenation.　This　provides　new　insights　to　develop　effective　hydrogenation　catalysts　based　on　metal　oxide.