Zn-Al composite coatings are widely used as protective coating for heat exchanger tube of open rack vaporizer, but suffered from corrosion damage and thus limited its service life. Enamel coatings, a high-performance inorganic non-metallic material, widely adopted in petrochemical industry, represent a promising alternative approach. Therefore, four types of enamel slurries were prepared by adding nano-Al₂O₃ particulates in the designed wet frit power, namely the frit powder with 0, 2, 4 and 6 mass% nano-Al₂O₃ particulates were prepared respectively, which were further ground by ball mill, subsequently applied on Al-alloy by cold spraying method and finally sintered at 550℃ to gain coatings/Al-alloy. The microstructure and surface morphology of the coatings were characterized using. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray photoelectron spectroscopy (XPS), laser confocal microscopy, and scanning electron microscopy (SEM). Their corrosion behavior was comparatively examined via immersion tests in 3.5%NaCl solution whilst with electrochemical measurement. The results indicate that during the sintering process, Al₂O₃ incorporates into the silicate network by capturing non-bridging oxygen and forming [AlO₄] structural units, thereby promoting the expansion and densification of the amorphous network. Among others, the coating containing 4%Al₂O₃ exhibits the best corrosion resistance, which may be ascribed to its dense network structure that acts as an effective barrier against corrosive medium penetration, extends the diffusion path, and suppresses crack initiation and propagation.