The detector is the core component of the photoelectric conversion in the satellite-borne, and once launched, it is almost impossible for the maintenance, repair and replacement. Using The screened commercial infrared detector without life data has the risk. The service life of the thermoelectric cooler(TEC) is the weak link of the life of detector assembly, and its reliability has an important influence on the normal use of the detector. Therefore, it is important to study the life test of the infrared detector assembly. Firstly, the working mode of the satellite-borne infrared detector and the failure mechanism of TEC were analyzed. The accelerated life test method with constant stress combined with fixed number truncation was developed to reduce the time cost.Secondly, the hardware and software of the infrared detector life test system was described in detail, demonstrated the equipment and temperature cycle of the infrared detector; Finally, the life test system was operated, the test time accumulated for about 170 days, and the temperature cycle of the infrared detector accumulated about 30 000 times. The test result indicated that the maximum changes of the relative photosensitivity of G12180 and G12183 were 1.45% and 4.44%, respectively. The maximus increments of the cooling current of G12180 and G12183 component TEC were 4.30% and 7.50%, respectively. It can be seen that the life and performance changes of the detector assembly meet the aerospace load requirements.