The application, design and preparation of a 2.06 μm laser polarizing film in the near-infrared solid-state laser are introduced. Based on the basic theory of thin-film optics and the comparison of three different membrane structures, the initial membrane structure is determined. Relevant technical issues such as film selection, pass-band ripple compression, and process preparation are discussed. The membrane structure is repeatedly optimized by computer optimization software. The polarizing film is prepared by electron beam vacuum evaporation and ion source assisted deposition, and its spectral detection is performed. Then, the relevant parameters in the preparation process are optimized according to the test results. Finally, the laser polarizing films with excellent optical properties, low film absorption, good uniformity and high stability are prepared.