This paper deals with an environment-friendly anodizing oxidation process for AZ31 magnesium alloy. Good anti-corrosion anodizing oxidation coating was prepared on the surface of AZ31 magnesium under 10 mA/cm2 constant current at 20°C after 20 min. The anodic film of AZ31 was ivory-white, dense, uniform, compact and porous structure. The anodic film of AZ31 mainly consisted of MgO, Mg2SiO4.According to Tafel curve and EIS,the anodic film of AZ31 had better anti-corrosion property than the substrate AZ31. This anodic film could increase the anti-corrosion property of AZ31 effectively.