Infrared color separation filtering device and preparation method thereof

The invention relates to an infrared color separation filtering device and a preparation method thereof. The infrared color separation filtering device comprises two obtuse-angle prisms, namely a first prism and a second prism; the surfaces, corresponding to the obtuse angles, of the first prism and the second prism are glued through glue, and the included angle alpha between the glued surface and the light path incident surface A meets the following condition that alpha is larger than or equal to 32 degrees and smaller than or equal to 48 degrees; and an infrared light splitting film is arranged on the first gluing surface of the first prism. The infrared light splitting film transmits infrared light of different wave bands to the corresponding analysis modules according to actual requirements. One part of the infrared light of the wave band penetrates through the infrared light splitting film and is emitted from the C surface of the first prism through the first prism, and the other part of the infrared lig