Herewith a new process was proposed for preparing micro-arc oxidation coating on the surface of AZ91D Mg-alloy. The coating is formed in a modified zirconium salt-based electrolyte that incorporates properly polyaniline (PAN) particles. Then its microscopic morphology and crystal structure were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Mechanical properties were evaluated through the Shore A scale method and friction-wear tests, while corrosion resistance was assessed via galvanostatic polarization curves, impedance measurements, hydrogen evolution experiments, and salt spray testing. The results show, that when the doping amount of polyaniline particles is 3.0 g, the porosity of the coating is reduced from the 13.16% for the coating prepared in the un-modified electrolyte to 4.81%, the friction coefficient is small, and the adhesion grade is 0; the coating has free-corrosion potential of -1.558 V, free-corrosion current density of 39.3 μA·cm^-2, resistance of 44037.9 Ω·cm², and hydrogen evolution of only 1.7 mL after immersion in 3.5%NaCl solution for 120 h, and a salt spray corrosion grade of 10G after 120 h. In conclusion, the doping of polyaniline particles is beneficial to the formation of a compact micro-arc oxidation coating. As the doping amount increases, the microstructure and corrosion resistance of the coating are significantly improved. Thus, preparing compact micro-arc oxidation coatings through polyaniline particle doping is an effective method to enhance the corrosion resistance of Mg-alloys.