Hydroxylamine,　as　an　important　reducing　agent,　disinfectant,　foaming　agent,　and　biocide,　plays　a　role　in　both　human　life　and　industrial　production.　However,　its　synthesis　is　confronted　with　challenges,　such　as　high　pollution　and　large　consumption.　Here,　we　propose　a　coordination　tailoring　strategy　to　design　47　graphene-supported　single　iron　atom　catalysts　(SACs),　namely,　Fe@C　x　Z　y　(Z　=　B,　N,　O,　P,　and　S),　for　the　reduction　of　nitric　oxide　to　hydroxylamine.　Using　density　functional　theory　calculations,　we　demonstrated　the　great　impact　of　the　coordination　environment　on　the　stability,　catalytic　selectivity,　and　activity　of　the　Fe　site.　We　identified　that　the　experimentally　available　Fe@N4　possesses　an　ultralow　theoretical　limiting　potential　of　-0.32　V　compared　to　that　of　other　catalysts.　A　comprehensive　investigation　of　the　electronic　properties　elucidates　the　underlying　active　origin　and　reaction　mechanism　of　the　nitric　oxide　reduction　reaction　to　hydroxylamine　on　Fe@N4.　These　results　not　only　explain　the　catalytic　origin　of　synthesized　SACs　for　the　NH2OH　production　but　also　offer　theoretical　guidance　for　further　optimizing　high-performance　catalysts.