The typical daytime color imaging technology can not acquire color images at night due to low illumination.Thus a three-primary-color image dynamic acquisition method adaptive for Low-Light-Level (LLL) condition is proposed.A filter wheel is used for filtering the reflected light,an image intensifier amplifies the monochrome light,the image sensor captures the monochrome images on image intensifier,thus to implement dynamic acquisition of three-primary-color images under LLL condition.Direct mapping method is adopted so as to fuse the three-primary-color image into a color image,and the objective non-reference assessment method is used to assess the quality of the fusion color images.Experimental results show that: 1) Under LLL condition,the “separation-amplification-fusion” scheme is feasible for acquiring a color image both in theory and practice; and 2) The brightness and contrast of color images can be enhanced by lengthening the exposure time.This research can be used as a reference for the design and development of color imaging system under LLL condition.