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　nonnoble　metal　HER　catalyst.　Furthermore,　we　find　descriptors　of　Delta　dp　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.