Abstract: The micromechanism interacting between optical field and high polymer is analyzed, the polarization process of high polymer and small molecule under the effect of the light field is introduced. The distribution of polarization on the high polymer chain which has been polarized is analyzed in narrowbeam optic field. The analysis indicates that for the tensionthinning film made from polymer, the dipole model can not be used to explain the mechanism interacting between high polymer and optic field. An antenna model is adopted and investigated in detail. The polarization formula of high polymer chain of aerial mode is theoretically derived, and its validity is verified through calculating the polarization distribution with DVM. Assuming the polarization distribution is the same as the distribution of the electric current on the aerial, the angle distribution of the aerial secondary radiation is calculated, and the modification factor of electric dipole model is obtained.