Glycerol (C₃H₈O₃), an organic waste generated by the biodiesel industry, has recently been proposed as a valuable green additive. The influence of glycerol on the morphology, composition and corrosion resistance of ZK60 magnesium alloys during the plasma electrolytic oxidation process has been investigated. The adsorption behavior of C₃H₈O₃ molecules on Mg (002) surface has been studied by using molecular dynamics simulations. Results predict that C₃H₈O₃ could be used as a promising leveler during the plasma electrolytic oxidation process. The silicate electrolyte with glycerol could increase the unit-area adsorptive capacity of the negative ions at the anode–electrolyte interface, and thus improves the smoothness and corrosion resistance of the coating.