In order to analyze the problem of the increase of blind elements in the long-wave HgCdTe detector under high and low temperature environments, the long-wave HgCdTe detector assembly is tested through experiments and the output images are observed. It can be found that the corrected detector image changes after changing the ambient temperature. Analyze the cause and verify it experimentally. The results show that the ambient temperature can affect the output image and performance of the detector, that is, changes in the operating temperature of the chip can cause changes in dark current and wavelength.