Infrared gas sensor is often used in the detection of sulfur hexafluoride gas. By measuring the infrared absorption spectra of air and sulfur hexafluoride gas, we understand the spectral requirements of the filter based on non-dispersive infra-red (NDIR) gas sensor. Then, monocrystalline silicon is selected as substrate, and germanium and zinc sulfide are selected as high and low refractive index materials separately. Two kinds of film structures, narrow-band pass film structure and cut-off film structure, were designed. The infrared filter with central wavelength of 10.562 μm, bandwidth of 175 nm, peak transmittance of 80.2% and cut-off range of 2～18 μm (except the pass band) , was prepared by selecting reasonable process parameters. Finally, the filter met the engineering application by environmental test and sensor test.ental test and sensor test.