To improve the long-term corrosion resistance of 7075Al aluminum alloy, the Al₂O₃ coating was prepared firstly by cathodic liquid plasma electrolysis technology, and then the graphene oxide coating was further prepared on the surface of the Al₂O₃ coating by pulsed electrodeposition technology to fill the micro-cracks and micro-holes. The phase composition, surface morphology, electrochemical properties, impedance value and macroscopic surface morphology of the deposited coatings were analyzed by various analytical methods. The results showed that the impedance value of 7075Al coated with single Al₂O₃ coating was still 4.6 Ω.cm₂ ^{after soak} of 25 days, which was much higher than the 3.2 Ω.cm₂ ^{of 7075Al}. However, several etch pit was observed on the Al₂O₃ coating after soak of 25 days due to the oxygen and chloride ions enter the interior of 7075Al through the micro-cracks and micro-pores. Thereafter, uniform and dense BTESPT/rGO composite coating was successful prepared by the pulsed electrodeposition technique under the 0.8 V deposition voltage. The BTESPT/rGO composite coating perfectly filled with the micro-cracks and micro-pores produced in the process of Al₂O₃ coating deposition. During soak of 105 days, the impedance value of 7075Al coated with Al₂O₃/BTESPT/rGO composite coating varied from 5.45 Ω.cm₂ ^{to 5.71 Ω.cm₂}. Furthermore, only slight color changes were observed on the surface of Al₂O₃/BTESPT/rGO composite coating, which exhibited excellent long-term corrosion resistance.