Compared with massive magneto-optical (MO) crystals, the one-dimensional MO photonic crystals, which are composed of magneto-optical and dielectric films per iodically or quasi-periodically, have a notable enhancement in MO effects, so t hey are very useful for fabricating micro-size MO isolators with only tens of m icrons in thickness. Our theoretical calculations are based on a transfer matri x method that is suitable to solve the problems of the propagation of polarized light in anisotropic media at an oblique incident angle. Using this method, we h ave discussed the working stability of two particular types of “sandwiched" ref lection-mode MO multilayer film isolators with the change of incident angle and film thickness at λ=1053μm. It is revealed that the structure with a thicker central MO medium has the advantages of better working stability and les s necessary layers.