Dark currents in HgCdTe devices are the main factor that limit detector performance in infrared imaging systems, which may result in a reduced dynamic range and poor signal-to-noise ratio (SNR). In this paper, the theoretical limit of dark background correction is defined, and the correction effects of different methods are quantitatively evaluated. Based on accurate measurements of the focal plane array (FPA) temperature, the relationship between the FPA temperature and dark background is evaluated. The fluctuations are highly consistent; thus, the FPA temperature can be used to estimate the dark background of different pixels in real time. Moreover, the temperature of the opto-mechanical components is stabilized at 120 K to suppress instrument radiation, and the temperature of the electrical box is applied to correct gradient changes in the dark background at large time scales. As a result, the dark backgrounds of different pixels can be accurately corrected in real time.