The micro-arc oxidation of ZK60 magnesium alloy was carried out in silicate electrolyte systems with different electric parameters. Through experimental analysis, the results are as follows: Time has a greater impact on the corrosion resistance of the coatings. When the film grows to a certain thickness, the corrosion resistance of the coating declines with the increase of time. With the increase of current intensity, the morphology of the coating becomes rougher， the micro hole becomes bigger and micro cracks are evident. The concentration of KF in the electrolyte has a great influence on the quality of PEO films. With the concentration of 12 g/L KF in the electrolyte, the thickness of the film is nearly twice of the film without KF addition, and the corrosion resistance of the film has also been greatly improved. When the concentration of fluoride is too high, the film is easy to delaminate from the sample surface. The addition of nano-SiC particle in the electrolyte has no obvious effect on the corrosion and thickness of the micro arc films.