The sluggish kinetics of oxygen evolution reaction (OER) is the key tailback for hydrogen production from the water electrolysis. Masking OER with thermodynamically auspicious methanol oxidation reaction (MOR) can significantly boost the H₂ and value-added products production. However, it is currently challenging to achieve a synergistic manipulation of product selectivity and performance for MOR electrocatalyst. Herein, we report NiSnPH@OOH/CC (CC = carbon cloth) perovskite hydroxide nanosphere as an efficient MOR electrocatalyst with high activity, stability, and selectivity towards methanol oxidation to formate. A surface amorphous layer of defect rich NiOOH was generated in operando by selective Sn leaching with stable perovskite hydroxide bulk structure, which mitigates the oxidative power and optimizes the local coordination environment of the active NiOOH sites. In situ Raman combined with electrochemical studies further confirm the key active species, NiOOH, generated in operando enhance the MOR and blocking the over oxidation of methanol to CO₂. As a result, NiSnPH@OOH/CC effectively masks the OER and attains > 99% selectivity with 100% Faradic efficiency for methanol-to-formate. The results of this study show the advances of NiSnPH@OOH/CC as an efficient electrocatalyst for MOR and also suggest its potential applications for various small organic molecules oxidation.