Uniform microarc oxidation coatings on the friction stir weld (FSW) joint of 5083 aluminum alloy were prepared by microarc oxidation (MAO) technique. The corrosion resistance of the friction stir weld joint before and after microarc oxidation surface treatment was evaluated by potentiodynamic polarization test and electrochemical impedance spectroscopic analysis (EIS). The results show that by microarc oxidation surface treatment, the corrosion current density of friction stir weld samples is decreased, and its electrochemical impedance is increased, thus the corrosion resistance of coated samples being significantly improved. In addition, the corrosion behavior at Fsw microstructure zones without MAO surface treatment have rather obvious difference, but after MAO treatment, both the coated base metal and Fsw joint on 5083 aluminum alloy have similar surface morphology and corrosion resistance.