According to polarization imaging theory, at least three linear polarized images of the same scene were required. A polarization imaging system based on division of aperture technique was designed in this paper so that the moving objects or a rapid changing scene was able to be imaged simultenously. The system MTF in all the view fields at 56 lp/mm was no less than 35% after optimization. Finally, polarization imaging experiments were conducted in a low light level condition and experimental results were analyzed qualitatively. Moreover, polarization imaging precision versus illumination was intestigated. By changing the incident illumination level and computing the acquired polarization images, the degree of polarization and angle of polarization were compared with the corresponding true values. The results show that polarization imaging can improve the quality of low light level images.