Abstract: To further improve the corrosion resistance and antibacterial property of micro-arc oxidation(MAO) coating prepared on magnesium alloy, two kinds of silver sols of A and B prepared by adjusting the amount of AgNO₃ was added into the silicate-based electrolyte. The effects of silver sol on coating thickness, microstructure, phase and element composition as well as chemical bonding state of elements were studied by TT260 digital eddy current thickness gauge, SEM, XRD and XPS. At the same time, the corrosion resistance and antibacterial property of the coating were measured by electrochemical workstation and plate colony counting method. The results show that adding silver sol into MAO electrolyte increases the thickness of the coating, and reduces the the size and number of micropores in the coating to some extent, simultaneously introduces Ag₂O₂ into the coating, which enhance the corrosion resistance and antibacterial property of the coating. Moreover, when the amount of AgNO₃ used in the preparation of silver sol is 0.2 mol/L and the addition amount of the obtained silver sol (B sol) is 5vol%, the corrosion resistance of the coating is the best, which is nearly 4 and 2 orders of magnitude higher than that of magnesium alloy substrate and coating produced in the electrolyte without silver sol, and is 48.7% higher than that of the same amount of A sol (0.1 mol/L AgNO₃).