Abstract: Microfocus radiography is being applied more and more because of its superiority in imaging. The developments of microfocus X-ray equipment and the physical theory of the X-ray imaging based on certain size focus were introduced. Microfocus could improve the unsharpness, magnification, scatter attenuation and the flaw detectability. Compared with the traditional technology, microfocus technology has many advantages to be used in CT or other digital inspection fields.