Based on the theory of propagating electromagnetic plane waves in homogenous anisotropic media and 4×4 matrix method, the Kerr spectra for the MnBi multilayered films as a function of wavelength, incident angle and layer number are simulated. It is found that the calculated Kerr spectra as a function of wavelength are in good agreement with the experimental ones for MnBi,Mn0.53Bi0.47，Mn0.52Bi0.44Sb0.04. In addition, the Kerr spectra as a function of incident angle and layer number for the MnBi multilayered films are simulated. The calculated results indicate that the magnetic layer number and incident angle greatly affect the Kerr spectra. A maximum Kerr rotation exists at some thickness of the magnetic film as the wavelength of the incident light is normal. Also, a maximum rotation is found in the simulated Kerr rotation as a function of incident angle at a fixed thickness of magnetic layer. These simulated results is important for the design of the materials.