In CO2 electroreduction, mutative intermediates and the challenging CC coupling necessitate the spatial interplay between active sites and through dynamically optimizing configurations. Herein, we anchor ethylenediaminetetraacetic acid (EDTA)-bonded Cux+/Bi3+ pair within UiO-66 for a spontaneous spatial-optimizing CO2-to-C2H4 electroreduction. Ab initio molecular dynamic (AIMD) simulation visualizes that such metal pair adaptively interacts with intermediates. Density functional theory (DFT) elicits the componential synergy, in which an upshift d-band of Cu activates CO2 being protonated into *COOH while Bi site stabilizes oxygenated dimers for deep hydrogenation. The dynamic feature of such pair affords large freedom for sorption and migration of various intermediates, which consequently bestows UiO-66-EDTA/CuBi a maximal FEC2H4 of 47 % and a total current density over 100 mA cm−2 in the flow cell.