The invention relates to a unit-type dual-band infrared detection assembly suitable for a low-temperature environment. The unit-type dual-band infrared detection assembly mainly serves as a photovoltaic conversion sensor at the front end of a signal chain, and is especially suitable for the analysis and application field of broadband infrared spectrum under the low-temperature environment, wherein the low-temperature environment is an environment, where the temperature is lower than 80 K, preferably, 60 K-80 K; and the broadband, in the example, is 2.5-13.3 [mu]m infrared wavelength. A Dewar cavity is utilized to enable a color separation film to be packaged with two types of unit-type detectors, thereby effectively solving the problem of broadband coverage hard to be realized by single type of detector Dewar package; the detection assembly can combine a refrigerating machine to realize work under the low-temperature environment; and a pre-amplification circuit is integrated in the assembly in the form of a chip module, so that system noise can be further suppressed, and a voltage signal can be output directly.