Aluminum is an attractive anode material for electrochemical energy storage and conversion devices, but the passive film and parasitic corrosion of aluminum anode in aqueous solution limits its development. Herein, we investigated the electrochemical performance of Al-2Mg alloy in alkaline electrolyte containing stannate ion via hydrogen evolution tests, electrochemical measurements and surface analysis. It is found that the solid-solute magnesium in aluminum matrix activates the oxide film and decreases the cathodic sites, which negatively shift the aluminum anode potential. Furthermore, the doping magnesium ion in the oxide film facilitates the tin deposition reaction on the surface of aluminum anode, and the uniformly deposited tin inhibits the parasitic corrosion reaction. As a result, Al-2Mg alloy in 6 M NaOH solution with 0.05 M Na2SnO3 exhibits low hydrogen evolution rate of 0.015 mL.cm(-2).min(-1) with the inhibition efficiency of 95% at open circuit and negative electrode potential of -1.81 V vs. saturated calomel electrode at 20 mA cm(-2).