The variation of dark current is the key factor influencing the accuracy of the signals of detectors in the short-wave infrared(SWIR) band. Firstly, based on the analysis of the working principle of infrared detector G5853-21, an experiment was designed aiming to find the relation between dark current, temperature and reverse bias of the detector. Also, an error model was given for the infrared polarimeter by considering the influences of dark currents. Error models for Stokes parameters and the degree of polarization have been built for the polarimeter. Allowing for the specific conditions in the space environment,an optimization was designed to reduce the impacts of dark currents and temperature requirement was also given for the infrared polarimeter. The results indicated that, with accurate control of the temperature, the error of the degree of polarization, involving the measurement uncertainity and other noises, could be below 0.42%(with p=0.3).