In order to study the radiation damage mode and characterization of the camera system with CMOS active pixel sensor as the photosensitive element, this paper uses the method of on-line radiation experiment, combined with the radiation interference noise suppression algorithm, to study the change of color video image information with the total radiation dose, and discusses the radiation life of the hardware under the irradiation of different total radiation doses and the effect of γ-ray radiation on the digital image information. Results show that the mode of γ-ray radiation damage of the camera is mainly reflected in the light transmittance decrease caused by the radiation damage of the lens, the dark current increase, distortion and damage of the sensor, and the instantaneous damage of the main board. The total radiation dose effect of the sensor mainly results in the increase of background noise, and most of the noise signals are concentrated in the dark part of frames. The increment of the average pixel value in the gray stripe of the image caused by the dark current is far less than the decrease of the average pixel value caused by the lens radiation damage. The exposure compensation function of the camera will carry out global compensation processing after detecting the decrease of video image brightness, which increases the pixel values of all pixels. The relationship between the video image information and total ionizing dose can be used as a method to calibrate the failure probability of the CMOS active pixel sensor camera, which can improve the reliability of the application for this kind of video monitoring system in the radiation environment.