<p>Metal covalent organic frameworks (MCOFs) hold significant promise for applications in photocatalytic carbon dioxide reduction reaction (CO₂RR). While diketimine COFs have the ability to chelate with metals to form MCOFs, the synthesis of ketimine COFs has been seldom reported due to the challenges associated with the characteristics of ketones. This study presents a straightforward strategy for synthesizing MCOFs featuring diketimine structures to enhance photocatalytic performance. We utilized acenaphthenequinone (Ace), which contains a diketone structure, in conjunction with the photosensitive monomer 1,3,6,8-tetra(4-aminopheny) pyrene (TAPPy) to create an AA stacking metal-free diketimine COFs, designated as TACOF-AA. Furthermore, under the same synthesis conditions, the simple addition of NiCl₂·6H₂O facilitated the successful preparation of an AB stacking Ni-based MCOFs, referred to as Ni-TACOF-AB. The metal Ni coordinated by MCOFs can not only serve as an active site for CO₂RR, but also significantly improve the efficiency of electron-hole separation. The photocatalytic CO₂RR test demonstrated that the CO evolution rate of Ni-TACOF-AB reached 11.71 mmol g⁻¹ h⁻¹, with an impressive selectivity of 99.9%. Remarkably, this rate is 7.6 times higher than that of TACOF-AA. Density functional theory (DFT) calculations further reveal that Ni-TACOF-AB can effectively lower the activation energy barrier associated with the rate-determining step in the CO₂RR. The Ni atoms regulate the local charge distribution of the material, facilitating the electron transfer of to the adsorbed CO₂ molecules. This research not only presents an appealing strategy for synthesizing ketimine-based COFs but also offers insights into modifying interlayer stacking modes.</p>