Abstract: In order to select the type of image sensor module which is suitable for γ-ray irradiation environment and has the most potential ability for radiation hardening, seven types of image sensor modules were studied by analyzing the parameters of bright and dark images before and after irradiation. The radiation resistance of different types of analog and digital image sensor modules was studied, and the radiation damage mechanism was also discussed. The experimental results show that the damage and interference degree of the image sensor module is related to the module type, the process of the image sensor, the irradiation dose rate and the total dose. The radiation damage does not show simple linear relationship with the dose rate. The light transmittance of the camera lens decreases with the increase of the total dose. The interference by the incident γ-ray on the quality of the collected pictures is related to the intensity of the ambient light, and the weaker real signals are more likely to be flooded by noises induced by the incident γ-ray. As a conclusion, the primary damage and interference of the incident γ-ray on the image sensor are caused by the dark current and positive pulse noise in each pixel. According to the experimental analysis, digital module using CMOS technology is more suitable for online monitoring in radiation environment, but it is still necessary to improve the reliability and service life by means of radiation hardening.