A symmetrical ferromagnetic bilayer film is investigated under the nonperiodic boundary condition and considering anisotropic field at two surfaces,by using the rescaling interface approach. 在非周期性边界条件和在考虑表面各向异性场的情况下,应用界面重参数化方法精确求解了两层对称铁磁薄膜中的低能自旋波本征问题。