The 1200℃ steam oxidation behaviors of CrAl coating with components deposited on Zr-4 were studied .The Cr₇₀Al₃₀ coating showed the best antioxidant properties .The Cr coating showed superior protection with a continuous Cr₂O₃ oxide layer .The Cr₅₀Al₅₀ coating exhibited partial protective properties，and presented continuous Cr₂O₃ and Al₂O₃ oxide layers .The Cr₃₀Al₇₀ coating had poor antioxidant resistance, with a large number of defects emerged on oxide layer. The effects of Al  diffusion and partical concentration oxidation resistance were discussed in detail.
 

Multi-ion plating ;CrAl coating；steam oxidation behavior; diffusion mechanism