Abstract: The hafnium dioxide thin films were prepared by using ion beam in substrate clean, deposition and posttreatment of films. The optical performance, surface characteristics and laser damage of the films were tested and analyzed. Experiment results show that the application of ion beam deposition in clean of substrates can wipe off polishing powder particle, enhance surface adsorption and increase stacking density. The application of ion beam deposition in deposition of thin films can improve thin films structure, decrease absorption of moisture, and increase damage threshold. The application of ion beam deposition in post-treatment can reduce surface roughness and improve damage threshold．