Temperature distribution of TiO2 single layer irradiated by 10ns, 1.06μm wavelength laser pulse was calculated with thermal transfer equation. Following conclusions were obtained; to improve thermal parameters of coating can reduce the peak temperature obviously, the thermal parameters of substrate have little effect on temperature response of coating, temperature distribution of thin film depends on the electrical field distribution. The peak temperature of coating with a quarter-wavelength optical thickness is lower than that of coating with a half-wavelength optical thickness.