[en] The availability of CMOS image sensor (CIS) digital module has been analyzed and studied as a monitoring and radiation warning equipment in the nuclear accident conditions. The radiation damage and the interference mechanism were studied based on the analysis of the color and the gray level information of three kinds of CIS modules in real time. The availability of the CIS digital module as a monitoring and radiation warning equipment is studied. The study proves that the CIS digital module can not only maintain a better monitoring picture quality, but also can reflect the intensity of the radiation field of the monitored environment in a short time radiation environment with low dose rate. Therefore, it is concluded that the CIS digital module can be used as a real time monitoring and the dark image noise is related to the intensity of the radiation field in the monitored environment. (authors)