Abstract: The technology of digital radiography is the radiology which is available to obtain digital radiographs.The essential difference between digital radiography and film radiography is in two aspects. First,the detection of inspection signal replaces film by digital detector. Second, the digitization technique of image is used. The theory on digitization image has become the basic theory of technology of digital radiography. The technology system of digital radiography consists of detector system, exposure technique, imaging digitization technique,display and evalution of image and the control measures for technique stability.