The scientific community has been actively researching artificial photosynthesis to promote ecologically sustainable living and address environmental issues. However, designing photocatalysts with active sites that are effective for both CO₂ reduction and water oxidation remains a significant challenge. Thus, we present the development of a donor–acceptor covalent organic framework (D–A COF), that integrates two distinct metal coordination environments through structure–activity relationships. Either cobalt or nickel ion is anchored on the D–A COF backbone to create N-metal–nitrogen and N-metal–sulfur coordination configurations, serving as bifunctional reduction and oxidation active sites, respectively. Remarkably, the as-synthesized Co-Btt-Bpy COF generated CO at a rate of 9,800 μmol g^-1 h^-1 and O₂ at 242 μmol g^-1 h^-1 under visible light irradiation. The CO generation rate was 127 times higher than that of pristine D–A COF. More importantly, Co-Btt-Bpy COF facilitates artificial photosynthesis with a CO release rate of 7.4 μmol g^-1 h^-1. The outstanding photocatalytic performance can be attributed to the synergistic interaction between the dispersed single-atom sites and Btt-Bpy COF, as well as the rapid migration of photogenerated electrons. In situ attenuated total reflection Fourier transform infrared (ATR FT-IR) spectra and theoretical calculations indicated that introducing Co sites effectively lowered the reaction energy barriers for the crucial intermediates *COOH and *OH. This work provides state-of-the-art designs of photocatalysts at the molecular level and in-depth insights for efficient artificial photosynthesis.