Rational　construction　of　platinum　(Pt)-based　single-atom　catalysts　(SACs)　with　high　utilization　of　active　sites　holds　promise　to　achieve　superior　electrocatalytic　alkaline　HER　performance,　which　requires　the　assistance　of　functional　supports.　In　this　work,　a　novel　catalytic　configuration　is　reported,　namely,　Pt　SACs　anchored　on　the　nickel-chromium　oxides　labeled　as　Pt　SACs-NiCrO3/NF.　The　mechanism　associated　with　the　metal-support　interaction　(MSI)　for　synergy　co-catalysis　that　empowers　efficient　HER　on　Pt　SACs-NiCrO3/NF　is　clarified.　Specifically,　the　modulated　electron　structure　in　Pt　SACs-NiCrO3　manipulates　the　interface　microenvironment,　mediating　a　more　free　water　state,　which　is　beneficial　to　accelerate　front　water　dissociation　behavior　on　the　oxide　support.　Besides,　the　homogeneously　distributed　Pt　sites　with　the　created　near-acidic　state　ensure　the　subsequent　fast　proton-involved　reaction.　All　these　determine　the　comprehensively　accelerating　HER　kinetics.　Consequently,　Pt　SACs-NiCrO3/NF　deliverers　considerable　HER　performance,　with　overpotentials　(eta　10/eta　100)　of　23/122　mV,　high　mass　activity　of　382.77　mA　mg-1Pt.　When　serving　in　an　alkaline　water-based　anion　exchange　membrane　electrolytic　cell　(AEMWE),　Pt　SACs-NiCrO3/NF　also　presents　excellent　performance　(100　mA　cm-2　at　the　cell　voltage　of　1.51　V　and　stable　up　to　100　h),　confirming　its　good　prospect.