The invention provides a far infrared spectrum detection low-noise pre-amplification circuit and relates to the technical field of signal detection. The far infrared spectrum detection low-noise pre-amplification circuit comprises a low-temperature detecting circuit, power circuits, a secondary amplification circuit and a plurality of filter circuits, wherein the power circuits are used for converting and outputting different direct current voltages and composed of a first power circuit and a second power circuit; the secondary amplification circuit is used for receiving signals collected by the low-temperature detecting circuit for differential amplification and is composed of a differential amplifier and a bias circuit, and the differential amplifier is composed of a first operational amplifier and a second operation amplifier; the plurality of filter circuits are used for eliminating noise of the power circuit and the secondary amplification circuit; the first power circuit suppliesa normal working direct current voltage for the secondary amplification circuit, and the second power circuit supplies a normal working direct current voltage for the low-temperature detecting circuit. The far infrared spectrum detection low-noise pre-amplification circuit can greatly reduce signal noise.