A widely used oxyanion corrosion inhibitor(Li_2CrO_4) was used as electrolyte additive(3.5 wt% Na Cl solution was used as electrolyte solution) for Mg–air battery. The potentiodynamic polarization tests showed that the presence of 0.1 wt% Li_2CrO_4in the Na Cl electrolyte reduced enormously the corrosion current density of the tested AZ31 Mg alloys.According to the intermittent discharge tests, the use of 0.1 wt% Li_2CrO_4 as electrolyte additive increased the anode efficiency of the Mg–air battery by 28.4%. The addition of 0.1 wt% Li_2CrO_4reduced the anode self-corrosion rate of the battery in the intermittent stage effectively. The product film after discharge was observed by scanning electron microscope, and the Mg–air battery containing 0.1 wt% Li_2CrO_4has a loose product film, which is beneficial to its discharge performance. So using Li_2CrO_4 as electrolyte additive could improve the intermittent discharge performance of Mg–air battery. And the use of oxyanion corrosion inhibitor as electrolyte additive may be an excellent way to improve the intermittent discharge performance of Mg–air battery. A widely used oxyanion corrosion inhibitor (Li_2CrO_4) was used as electrolyte additive (3.5 wt% NaCl solution was used as electrolyte solution) for Mg-air battery. The potentiodynamic polarization tests showed that the presence of 0.1 wt% Li_2CrO_4in the NaCl electrolyte reduced enormously the corrosion current density of the tested AZ31 Mg alloys. Accredited to the intermittent discharge tests, the use of 0.1 wt% Li 2 CrO 4 as electrolyte additive increased the anode efficiency of the Mg-air battery by 28.4%. The addition of 0.1 wt% Li_2CrO_4reduced the anode self-corrosion rate of the battery in the intermittent stage effectively. The product film after discharge was observed by scanning electron microscope, and the Mg-air battery containing 0.1 wt% Li_2CrO_4has a loose product film, which is beneficial to its discharge performance. So using Li_2CrO_4 as electrolyte additive could improve the intermittent discharge performance of Mg-air battery. And the use of oxyanion corrosio n inhibitor as electrolyte additive may be an excellent way to improve the intermittent discharge performance of Mg-air battery.