We made quantitative detection analysis to infrared polarization characteristics of target using a non-real time infrared polarization detection system. First, the detection system must be calibrated, so according to our detection system, we presented a calibration method of doing radiometric calibration in four polarization detection channels. Second, based on the analysis of the infrared polarized mechanism, we made some theoretical simulation models. The target infrared radiation include spontaneous radiation and reflected radiation, and the combination of them lead to depolarization effect. The energy distribution between spontaneous and reflected radiation of the target is affected by target temperature, light conditions etc. So we created a experimental environment of low temperature and reflected radiation to validate theoretical model of spontaneous radiation, and found the experimental data has good consistency with theoretical prediction in a certain error range.