Abstract Understanding the dynamical reconstruction mechanisms of the active phase in metal–organic frameworks (MOFs) during the course of oxygen evolution reaction (OER) is central to the development of efficient and durable OER catalysts, but remains elusive till present. Herein, a spatiotemporally decoupled reconstruction strategy is pioneered to engineer a dual‐metal‐node MOF ([Fe 3 O(hbdc) 3 ][Ni 2 (trz) 3 ]) catalyst (hbdc: 2‐hydroxyterephthalic acid, trz: 1,2,4‐triazole), in which orbitally coupled pore‐microenvironments drive time‐phased kinetic reconstruction of the spatially separated Fe/Ni metal nodes, creating a foundational platform to lay bare the mechanisms governing the reconstruction processes and the cross‐scale kinetic. Furthermore, a multimodal operando diagnostic platform is developed that integrates in situ X‐ray absorption spectroscopy (XAS), in situ Raman spectroscopy, and real‐time reaction kinetics tracing, to decipher the MOF atomic‐to‐mesoscale reconstruction kinetics from the Fe‐centered active phase to the NiFe‐centered more active phase. Crucially, the purpose‐partitioned pore architecture synergizes the interplay between the Fe─Ni nodes, while the self‐adaptive defects, bond relaxation, and structural regeneration collectively modulate the kinetic behavior, leading to the pronounced OER activity enhancement. This work establishes a structural dynamics tracking methodology that can integrate multi‐scale characterization techniques and provide deep insights into the reconstruction mechanisms, thus filling the critical gap in understanding structure‐activity relationships under operando conditions.