Abstract Constructing Cu 0 –Cu + double‐active sites is significant for C–C coupling to produce multicarbon products during the CO 2 electrocatalytic reduction process. However, Cu‐based precursors (including Cu + ) are easily reduced to Cu 0 , especially at large current densities. Thus, developing a facile Cu + stabilization method to form Cu 0 –Cu + double‐active sites is highly desirable but challenging. Herein, fullerene (C 60 ) is used as an electronic buffer to stabilize the Cu + site. Then, a composite of copper oxide and C 60 precursor is designed to obtain a catalyst consisting of in situ formed Cu 0 –Cu + double‐active sites. The catalyst not only delivers up to 61% multicarbon (C 2+ ) products Faraday efficiency at a partial current density of 366 mA cm −2 but also exhibits a good 12 h durability of the Cu + site at −1.4 V versus reversible hydrogen electrode. Moreover, the Cu 0 –Cu + double‐active sites are revealed to induce the preferential coupling of *CO and *CHO over *CO dimerization, accounting for the enhanced C 2+ selectivity.