The noise model and characteristics of the infrared detector in low temperature background were analyzed and experimentally researched. Detector noise calculation model and method of four parameters method were used in this paper. The experimental platform was set up for test the performance of the infrared detector under different low temperature. Results of the relationship of the low-frequency temporal noise, high frequency temporal noise, low frequency spatial noise, high frequency spatial noise respectively with temperature and integration time were obtained. Within a certain temperature range, experiments prove that low frequency temporal noise shows a strong correlation with temperature, low frequency spatial noise exhibited obvious nonlinear response of detector, high frequency noise is dependent on integration time significantly.