Abstract: The joint parts of 2A12 aluminum alloy and fiber-reinforced polymer matrix composite (with or without glass fiber protection layer) were prepared by the co-curing molding process. The electrochemical corrosion and salt spray corrosion tests were used to study the electro-couple corrosion behavior and corrosion resistance of the coupled system. SEM and XPS were combined to observe the morphology, composition analysis and corrosion mechanism research of the corroded samples. The results show that the average electric coupling current density of the coupled system with a glass fiber protection layer is 0.112 μA/cm², which is two orders of magnitude lower than that of the unprotected system. After salt spray corrosion, adding the glass fiber protective layer can reduce the degree of corrosion and delay the appearance of corrosion pits. Al₂O₃, AlOOH, and Al(OH)3 are present on the surface of the aluminum after salt spray corrosion.