Aiming at the using requirements of the military optical instrument,we deposit laser flat polarizer on substrate of K9 flat glass.With incident angle 56.4°,at the wavelength 1064 nm,TP is higher than 99%,TS is less than 1%,and the laser-induced damage threshold over 600 MW/cm2.We adopt electronic beaming vacuum depositing method with the aid of ion assistant deposition systems,chose HfO2 and SiO2 as the material of high and low refractive index,using Macleod software to design and analyse the film structure and LightRatioPeak as monitor method,through optimizing technical parameters and reducing thickness error,we successfully deposit polarizer on the substrate of K9 flat glass to achieve the requirements.The coating not only satisfies the spectral requirements,but also passes the environment testing,it perfectly meet the applying demand of military optical instruments.