Metal oxide of spinel family has performed great potential toward oxygen evolution reaction (OER), but the fundamental mechanism of spinel oxides is still far from being completely understood especially for the role of metal ions. Owing to various coordinated sites of divalent/trivalent metals ions and surface condition (morphology and defects), it’s a great challenge to have a fair assessment of electrocatalytic performance of spinel system. Herein, we demonstrated a series of MFe₂O₄ (M = Fe, Co, Ni, Zn) family with a well-controlled morphology to achieve comprehensive study of electrocatalytic activity toward OER, in which most of the divalent metals (M²⁺) of MFe₂O₄ were located at octahedral sites. By utilizing several analyses, we could conclude a universal rule toward the spinel metal oxide for oxygen evolution. The activities for OER in spinel metal oxide system were determined by the occurrence of phase transformation rather than electronic state of metal ions, and this structural transformation could work well in both crystallographic sites (Td and Oh sites). Additionally, the divalent metal ion significantly dominated the formation of oxyhydroxide through an epitaxial relationship which depended on the atomic arrangement in the interface of spinel and metal oxyhydroxide, while trivalent metal ions were likely to be hosts lattices. The metal oxyhydroxide was formed during redox occurrence rather than OER, while the redox occurrence with remarkable increase in resistance and capacitance might result from the structural transformation from spinel to metal oxyhydroxide. We believed that the approaching strategies and information obtained in present study can offer a guide to design a promising electrocatalytic system toward oxygen evolution reaction and other fields.