Abstract: Nonlinear second-harmonic polarization matrix from the anisotropy magnetic-optical thin film,numbers and distribution of elements of the matrix at different symmetrical surfaces have been provided.The nonlinear polarization of the corresponding surface and the nonlinear second harmonic field aroused by the corresponding surface of evenly reflection space for the magnetic-optical thin film is also presented,when the magnetization strength of magnetic self-surplus parallel to the 001,110 and 111 crystal surface respectively and the outside electric field does action to responding surface.The orientation angle of two possibilities of this harmonic smooth site is given.The cause factor and the reason of two possible orientations to correspondingly surface are analysized and discussed.