Multi-angle Polarization Imager (MAI) uses a back-illuminated area array CCD detector to quantitatively acquire cloud and aerosol parameters. Dark current is one of the main factors affecting the data quality of the area detector CCD and its quantitative application. In order to analyze the characteristics of CCD dark current and its channel dependence and improve the imaging quality of CCD, based on the analysis of the characteristics of MAI level 0 data, we propose a method for analyzing the dark current characteristics of each channel of MAI based on the nighttime scene. The period from February 2 to 16, 2018, MAI nighttime scene observation experiment is accomplished. Comparing the observations during daytime and nighttime of the MAI light blocking channels, the result shows that there is no significant difference in dark current characteristics observed in daytime and nighttime. Therefore, based on the night observation data, the dark current characteristics of 13 channels of MAI are analyzed. The results show that the distribution of dark current for each channel has some degree of non-uniformity and “bad points”, and the distribution within each channel has good stability, but it is significant difference for each channel. Based on the image method to correct “bad spots”, after correcting the non-uniformity distribution of pixels based on linear, non-linear relationship, the standard deviation of dark current images decrease from 12.1% to 6.9%. Taking the observation of the clear-air ocean as reference, the maximum possible impact of dark current and “bad points” on pixel observations decreased from 9.1% to 3.0%. The analysis results show that dark current monitoring based on nighttime observation can not only monitor the dark current characteristics of each channel, but also handle the channel dependence of dark current relative to setting dark current monitoring channel. Therefore, in the subsequent design of satellite-borne observation instruments, the dark current of each channel can be directly monitored and corrected by nocturnal observation, and there is not necessary to set a dark current monitoring channel separately, which will reduce the design weight of the load.