Electronic structure engineering via integrating two defect structures with opposite modulation effects holds the key to fully unlocking the power of a catalyst. Herein, for the first time, an interpolation principle is proposed to activate CoOOH via W doping and Co vacancy for oxygen evolution reaction (OER). Density functional theory suggests the opposite roles of W dopant and Co vacancy but a synergy between them in tuning the electronic states of Co site, leading to near-ideal intermediate energetics and dramatically lowered catalytic overpotential. Experimental studies confirm the modulation of the electronic structure and validate the greatly enhanced catalytic activity with a small overpotential of 298.5 mV to drive 50 mA cm-2 . The discovery of the interpolation between dopants and vacancies opens up a new methodology to design efficient catalysts for various electrochemical reactions. This article is protected by copyright. All rights reserved.