In order to study the mechanism of LWIR polarization detection, based on the detection of practical, this paper designed established a LWIR polarization detector. In a laboratory environment we carried out the performance testing of the detector. The test results showed that the detector had a good performance. Based on the result, the paper analyzed the factors that influence the detection. At the same time, the article pictured the typical targetsin the field, including the artificial target and natural environment. Through comparative analysis of the radiation imaging, the degree of polarization imaging and angle of polarization imaging, the results showed that the infrared polarization imaging had its unique advantages and characteristics, for practical applications there is a certain meaning and value.