With tunable local electronic environment, high mass density of MN4 sites, and ease of preparation, metal-organic conjugated coordinative polymer (CCP) with inherent electronic conductivity provides a promising alternative to the well-known M-N-C electrocatalysts. Herein, the coordination reaction between Cu2+ and 1,2,4,5-tetraaminobenzene (TAB) was conducted on the surface of metallic Cu nanowires, forming a thin layer of CuN4-based CCP (Cu-TAB) on the Cu nanowire. More importantly, interfacial transfer of electrons from Cu core to the CuN4-based CCP nanoshell was observed within the resulting CuTAB@Cu, which was found to enrich the local electronic density of the CuN4 sites. As such, the CuTAB@Cu demonstrates much improved affinity to the *COOH intermediate formed from the rate determining step; the energy barrier for C-C coupling, which is critical to convert CO2 into C2 products, is also decreased. Accordingly, it delivers a current density of −9.1 mA cm−2 at a potential as high as −0.558 V (vs. RHE) in H-type cell and a Faraday efficiency of 46.4% for ethanol. This work emphasizes the profound role of interfacial interaction in tuning the local electronic structure and activating the CuN4-based CCPs for efficient electroreduction of CO2.