Dual-atom　catalysts　(DACs)　are　promising　for　applications　in　electrochemical　CO2　reduction　due　to　the　enhanced　flexibility　of　the　catalytic　sites　and　the　synergistic　effect　between　dual　atoms.　However,　precisely　controlling　the　atomic　distance　and　identifying　the　dual-atom　configuration　of　DACs　to　optimize　the　catalytic　performance　remains　a　challenge.　Here,　the　Ni　and　Fe　atomic　pairs　were　constructed　on　nitrogen-doped　carbon　support　in　three　different　configurations:　NiFe-isolate,　NiFe-N　bridge,　and　NiFe-bonding.　It　was　found　that　the　NiFe-N　bridge　catalyst　with　NiN4　and　FeN4　sharing　two　N　atoms　exhibited　superior　CO2　reduction　activity　and　promising　stability　when　compared　to　the　NiFe-isolate　and　NiFe-bonding　catalysts.　A　series　of　characterizations　and　density　functional　theory　calculations　suggested　that　the　N-bridged　NiFe　sites　with　an　appropriate　distance　between　Ni　and　Fe　atoms　can　exert　a　more　pronounced　synergy.　It　not　only　regulated　the　suitable　adsorption　strength　for　the　*COOH　intermediate　but　also　promoted　the　desorption　of　*CO,　thus　accelerating　the　CO2　electroreduction　to　CO.　This　work　provides　an　important　implication　for　the　enhancement　of　catalysis　by　the　tailoring　of　the　coordination　structure　of　DACs,　with　the　identification　of　distance　effect　between　neighboring　dual　atoms.