<p>TBCs are crucial for enhancing the performance and longevity of gas turbine engines, especially in high-temperature and corrosive environments. This study, an Al plating layer was applied on the surface of the CoCrNiAlY-YSZ-LaMA dual ceramic coating by arc ion plating (AIP). Microscale analytical characterization methods were employed to comprehensively analyze the high-temperature corrosion behavior of the coatings during the sulfate exposure. The coating without Al layer exhibited significant volume shrinkage due to crystallization reactions, resulting in the sprouting and expansion of longitudinal micro-cracks. These micro-cracks acted as diffusion channels for O₂ and molten salts to the interior during the hot sulfate exposure, resulting in rapid TGO growth and severe elemental diffusion, ultimately forming a brittle spinel phase and exacerbating the coating’s fracture failure. In contrast, the coating with Al planting layer displayed better salt corrosion resistance and structural stability. During hot salt corrosion, the surface Al coating reacts in situ with O₂ to form a dense Al₂O₃ barrier layer, which effectively prevents or delays the internal diffusion of O₂ and molten salts, resulting in a slow growth of TGO. Although the mass of the coating increased slightly from 3.636 mg/cm² at 20 h to 5.041 mg/cm² at 80 h, the overall structure remained stable. The results of this investigation indicate that the Al plating layer plays a significant role in enhancing the corrosion resistance and extending the service life of the coatings, providing new insights for the application of ceramic coatings.</p>