In this paper, colloidbased single-layer SiO2 and ZrO2 thin films were deposited on K9 glass and silicon wafer substrates by Sol-Gel spin-coating method. The films were irradiated by a Q-switched Nd:YAG high power laser whose wavelength was 1064nm and its pulse width was 15ns. The morphologies of the damaged films were observed by SEM and microscope. Damage mechanics of the laser were studied. The results show that solventexchange , UV-irradiation and the addition of PVP are effective methods to improve the laser damage threshold of SolGel thin films.