Abstract: In order to investigate effect of the stress on the thin film polarizing beam sputters and seek the techniques to reduce stress.prior to the deposition polarizing splitter coatings,Al203 buffer layer was coated,the degree of vacuum was improved,the substrate temperature was increased, the film deposition rate was slowed down during deposition processes.During encapsulation process,optical photosensitive adhesive rapid solidification under UV irradiation was used. The spot images of reflected light and transmitted light of the thin film polarizing beam sputter were collected with CCD before and after process improvement respectively.The extinction ratios of reflected light and transmitted light of the thin film polarizing beam splitter were measured before and after process improvement respectively. The results indicate that after applying improved technologies, the spot energy of reflected and transmitted light is more concentrated, speckle phenomenon becomes smaller; the extinction ratios characteristic of reflected and transmission light dramatically are improved.Thus,thin film polarizing beam sputters can reach the application requirements by optimizing the process and packaging technology.