Abstract Electrochemically driven carbon dioxide (CO 2 ) conversion is an emerging research field due to the global warming and energy crisis. Carbon monoxide (CO) is one key product during electroreduction of CO 2 ; however, this reduction process suffers from tardy kinetics due to low local concentration of CO 2 on a catalyst's surface and low density of active sites. Herein, presented is a combination of experimental and theoretical validation of a Ni porphyrin‐based covalent triazine framework (NiPor‐CTF) with atomically dispersed NiN 4 centers as an efficient electrocatalyst for CO 2 reduction reaction (CO 2 RR). The high density and atomically distributed NiN 4 centers are confirmed by aberration‐corrected high‐angle annular dark field scanning transmission electron microscopy and extended X‐ray absorption fine structure. As a result, NiPor‐CTF exhibits high selectivity toward CO 2 RR with a Faradaic efficiency of >90% over the range from −0.6 to −0.9 V for CO conversion and achieves a maximum Faradaic efficiency of 97% at −0.9 V with a high current density of 52.9 mA cm −2 , as well as good long‐term stability. Further calculation by the density functional theory method reveals that the kinetic energy barriers decreasing for *CO 2 transition to *COOH on NiN 4 active sites boosts the performance.