Economical　and　efficient　catalysts　for　the　hydrogen　evolution　reaction　are　critical　for　realizing　the　large-scale　application　of　water　splitting.　Herein,　a　floral　microspheres　heterostructure　of　Mn-doped　NiC/NiO　catalyst,　synthesized　using　a　simple　hydrothermal　and　vapor　deposition　method,　is　reported.　The　results　demonstrate　that　doping　Mn　into　NiC/NiO　can　regulate　both　the　microstructure　and　electronic　structure,　significantly　improving　the　catalytic　performance　for　electrochemical　hydrogen　evolution　reaction.　In　the　1　M　KOH　solution,　the　current　density　of　10　mA　cm−2　required　overpotential　is　only　56　mV,　its　Tafel　slope　is　56.4　mV　dec−1,　and　the　higher　current　density　100　mA　cm−2　required　overpotential　is　only　200　mV.　Also,　the　Mn–NiC/NiO　catalyst　exhibit　a　considerable　stability.　After　24　h　catalytic　hydrogen　evolution　test,　its　microstructure　and　potential　show　negligible　change　under　200　mA　cm−2.　The　study　provides　a　method　to　develop　Mn-doped　nickel-based　heterostructure　as　an　efficient　and　potential　hydrogen　evolution　reaction　catalyst.　©　2025　The　Author(s).　Advanced　Energy　and　Sustainability　Research　published　by　Wiley-VCH　GmbH.