Based on the rigorous coupled wave theory,the phenomenon that the zero order reflection efficiency of rectangular subwavelength grating varies with the wavelength is studied when incidence angle,azimuth and grating parameters are variant.The relatively rational parameters of grating are chosen according to the calculated results to make that when incidence angle or azimuth is varied,the light of different wave band will be reflected.The result can be used as the basis for design and manufacturing of anti-counterfeiting grating.