The　discovery　of　superconductivity　in　layered　MgB2　has　renewed　interest　in　the　search　for　high-temperature　conventional　superconductors,　leading　to　the　synthesis　of　numerous　hydrogen-dominated　materials　with　high　critical　temperatures　(T-c)　under　high　pressures.　However,　achieving　a　high-T-c　superconductor　under　ambient　pressure　remains　a　challenging　goal.　In　this　study,　we　propose　a　novel　approach　to　realize　a　high-temperature　superconductor　under　ambient　pressure　by　introducing　a　hexagonal　H　monolayer　into　the　hexagonal　close-packed　magnesium　lattice,　resulting　in　a　new　and　stable　few-hydrogen　metal-bonded　layered　magnesium　hydride　(Mg-4)(2)H-1.　This　compound　exhibits　superior　ductility　compared　to　multi-hydrogen,　cuprate,　and　iron-based　superconductors　due　to　its　metallic　bonding.　Our　unconventional　strategy　diverges　from　the　conventional　design　principles　used　in　hydrogen-dominated　covalent　high-temperature　superconductors.　Using　anisotropic　Migdal-Eliashberg　equations,　we　demonstrate　that　the　stable　(Mg-4)(2)H-1　compound　is　a　typical　phonon-mediated　superconductor,　characterized　by　strong　electron-phonon　coupling　and　an　excellent　T-c　of　37　K　under　ambient　conditions,　comparable　to　that　of　MgB2.　Our　findings　not　only　present　a　new　pathway　for　exploring　high-temperature　superconductors　but　also　provide　valuable　insights　for　future　experimental　synthesis　endeavors.