TiO₂ and SiO₂ are selected as high and low refractive index materials, and the sapphire substrate wide cutoff high Q factor band pass filter is designed by traditional design method (the long wave and short wave pass film systems are plated on both sides of the substrate, with the thickness of 1.67 μm and 8.67 μm, respectively). In order to avoid the problem of large variation of filter one-sided shape caused by large difference of film thickness, the membrane system on both sides of the substrate is rearranged. After optimization, the number of film layers on both sides is 49 and 50, and the thickness of film layer is 5.73 μm and 4.22 μm, respectively. The thin films are plated by electron beam evaporation physical vapor deposition and the transmittance of the samples is measured by spectrophotometer. The experimental results show that the average transmittance of the sample in the passband (521-596 nm) is 96.59%, the average transmittance in the cutoff region is 0.076%, the rectangularity of the passband is 0.95, and the steepness of the transition zone on both sides of the passband is 0.89%. It has the characteristics of high Q factor filter. In addition, the experimental curve is in good agreement with the design curve, which verifies the effectiveness of optimizing the structure of the two-sided membrane system.