Abstract: According to the requirement of infrared radiation detection of low-temperature targets during the period of infrared payload serving in orbit, a low-temperature infrared radiation measurement scheme under vacuum condition was proposed, and the measuring device was developed. The measuring device was mainly composed of a low-temperature infrared optical system, a low-temperature mechanical structure, a low-temperature infrared detection system and a weak signal processing system. The low-temperature infrared radiation was gathered to the detector image plane through the optical system, the lock-in amplifier used coherent detection technology to extract the target signal, and the low-temperature infrared radiation was measured. After the development of the measuring device completed, the standard black body radiation source was used in the vacuum chamber to perform a low-temperature infrared radiation calibration test in the temperature range of 198 K to 423 K, which obtained the effective test data and the measurement uncertainty was within 5%. The proposed low-temperature infrared radiation measurement technology under vacuum condition can provide important data support for the design of low-temperature infrared target detection of infrared payload in orbital space.