Electrochemical reduction of CO2 into valuable chemical products could be realized by reasonable design of effective electrocatalysts with atomically dispersed active sites, but the task presents challenges for chemistry because of the lack of facile and scalable synthetic route. Therefore nitrogen-doped porous carbon supported Ni electrocatalyst is presented via a facile synthetic method. In the first step, commercial carbon black was oxidized by HNO3 to generate organic group followed by absorption of Ni ions. Secondly, calcination under NH3 atmosphere led to N doped carbon based Ni catalyst which exhibited excellent catalytic performance with approximate 95 % Faradaic efficiency for CO, which is helpful for chemists to reasonable design and scalable preparation of economical and efficient catalysts.