With the rapid development of terahertz radiation sources and detectors, there is also a great demand for terahertz filters. The quantitative studies on polarizer have been carried out in other spectral range, but the studies on terahertz wave polarizer are still very limited. Therefore, it is valuable to investigate the design of a polarizer in the terahertz range. In this article, tellurium and polystyrene thin film is used to compose a symmetrical structure, and then 10 periods of this structure are used in our design. A terahertz wave polarizer with micrometer scale is gained. Results of simulations show that the polarizer has a high performance in reflectivity for transverse-electric part polarized terahertz wave as well as low reflectivity for transverse-magnetic part polarized terahertz wave. The work frequency and incident angle of our design are 0.5 THz and 45°, respectively, and it has a reasonable incident angle range.