Carbon　-　based　single　-　atom　catalysts,　a　promising　candidate　in　electrocatalysis,　offer　insights　into　electron-　donating　effects　of　metal　center　on　adjacent　atoms.　Herein,　we　present　a　practical　strategy　to　rationally　design　a　model　catalyst　with　a　single　zinc　(Zn)　atom　coordinated　with　nitrogen　and　sulfur　atoms　in　a　multilevel　carbon　matrix.　The　Zn　site　exhibits　an　atomic　interface　configuration　of　ZnN4S1,　where　Zn＇s　electron　injection　effect　enables　thermal-　neutral　hydrogen　adsorption　on　neighboring　atoms,　pushing　the　activity　boundaries　of　carbon　electrocatalysts　toward　electrochemical　hydrogen　evolution　to　an　unprecedented　level.　Experimental　and　theoretical　analyses　confirm　the　low-　barrier　Volmer-Tafel　mechanism　of　proton　reduction,　while　the　multishell　hollow　structures　facilitate　the　hydrogen　evolution　even　at　high　current　intensities.　This　work　provides　insights　for　understanding　the　actual　active　species　during　hydrogen　evolution　reaction　and　paves　the　way　for　designing　high-　performance　electrocatalysts.