Infrared (IR) film systems can accumulate considerable stress due to their large thickness. In addition, the thermal stress of the films will further increase due to a significant difference in thermal expansion coefficient between the film materials and the substrate. Stress accumulation limits the passband transmittance of the 2.76 to 3.04  μm traditional IR interference filter to about 80%. To increase the passband transmittance and guarantee the mechanical properties, four kinds of samples were designed, prepared, and measured. Through matching the film systems and proposing an alternative deposition method, high-performance IR bandpass filters with an average transmittance of 92.2% have been prepared. The improved transmittance provides a necessary study of developing IR systems and improving imaging quality.