The transition metal with high valence state in oxyhydroxides can accelerate the reaction kinetics, enabling highly intrinsic OER activity. However, the formation of high-valence transition-metal ions is thermodynamically unfavorable in most cases. Here, a novel strategy is proposed to realize the purpose and reveal the mechanism by constructing amorphous phase and incorporating of elements with the characteristic of Lewis acid or variable charge state. A model catalyst, CeO₂-NiFeO_xH_y, is presented to achieve the modulation of valence state of active site (Ni²⁺→Ni³⁺→Ni⁴⁺) for improved OER, leading to dominant active sites with high valence state. The CeO₂-NiFeO_xH_y electrode exhibits superior OER performance with overpotential of 214 and 659 mV at 10 and 500 mA cm⁻², respectively (without IR correction), and high stability, which are much better than those of NiO_xH_y, NiFeO_xH_y and CeO₂-NiO_xH_y. These findings provide an effective strategy to achieve the active metals with high-valence state for highly efficient OER.