CrAl/CrAlN multilayer films were deposited by midfrequency unbalanced magnetron sputtering. The structure, mechanical features and corrosion resistance as a function of modulation periodicity of the films were also studied. The results show that all of the CrAl/CrAlN multilayer films have denser layered structure. The internal stress of the CrAl/CrAlN multilayer films becomes the compressive stress as the modulation periodicity increases, and the hardness of the films attains a maximum value when the modulation periodicity is 285.7 nm. Moreover，the modulation periodicity has a great effect on the corrosion resistance of the CrAl/CrAlN multilayer films. After 96 h salt spray corrosion test (3.5% NaCl), the CrAl/CrAlN multilayer films at the modulation periodicity of 142.8 nm are not corrosive at all, which show that the films have excellent corrosion resistance.