The effect of filter on the column density of polluted gas in the non-dispersive visible imaging system is studied. The relationship between central wavelength and incident angle is analyzed for the filter, and it is found that the central wavelength of the filter shifts toward the short-wave direction with the increase of the incident angle. When the incident angle reaches up to 40°, the center wavelength of the filter has a drift of 17.4 nm. The influences of different filters on the signal to noise ratio (SNR), linear response and sensitivity are also discussed. The research results show that the SNR can be increased by the increase of exposure time or by the image stack. The filter with a full width at half maximum (FWHM) of 10 nm possesses good sensitivity. At the same time, the linear response coefficient above 0.9 indicates that a filter with a FWHM of 40 nm can still satisfy the theoretical condition for resolving the column density of polluted gas in the non-dispersive imaging system. The detection limit for a filter with a FWHM of 10 nm is the best, which is about 4.475×10 16 molecule/cm 2. The optimal FWHM is between 2 nm and 40 nm for obtaining the column density of polluted gas. Based on the filter with a FWHM of 10 nm and a central wavelength of 450 nm, the two-dimensional spatial distribution map of NO2 column density is obtained by measuring remotely the smoke plume from the chimneys in one steel plant.