Molybdenum　diselenide(MoSe2)　has　attracted　great　interest　as　a　promising　nonprecious　metal　catalyst　for　hydrogen　evolution　reaction(HER).　However,　scarce　catalytic　sites　and　unsatisfactory　electrocatalytic　activity　seriously　impede　its　practical　application.　Single-　and　dual-atom　catalysts　play　a　crucial　role　in　catalyzing　of　HER　due　to　their　unique　electronic　properties,　highest　atom　utilization　and　synergistic　effects.　Herein,　we　screen　a　series　of　single-　and　dual-atom　3d-metals(Sc,　Ti,　V,　Cr,　Mn,　Fe,　Co,　Ni,　Cu　and　Zn)　doping　MoSe2　as　potential　HER　electrocatalysts　based　on　density　functional　theory　calculations.　All　3d-metals　doping　MoSe2　exhibit　highly　thermodynamically　and　electrochemical　stabilities,　which　show　significantly　promoting　adsorption-activity　by　3d-metals　dopants,　due　to　synergistic　interaction　between　active　Se　site　and　neighboring　3d-metals　dopants.　Specially,　we　screen　out　that　dual　Cu-Co-MoSe2　shows　the　best　HER　activity　with　low　overpotential(only　30　mV),　markedly　lower　than　single　Co-MoSe2(360　mV)　and　crystal　Pt(90　mV),　indicating　promising　candidate　for　non-noble　metal　HER　catalyst.　Furthermore,　we　find　descriptors　of　Δdp　and　ICOHP　can　well　predict　materials’　HER　performance　and　exhibit　linear　relationship　with　H-binding　strength.　This　study　will　provide　in-depth　understanding　for　designing　and　screening　of　high-efficiency　MoSe2-based　catalysts　for　HER.　©　2024　Elsevier　B.V.