X-ray optical phase contrast imaging system and method based on multi-frequency stripes

The invention discloses an X-ray optical phase contrast imaging system and method based on multi-frequency fringes, and the system comprises a light source focusing module which is used for the collection and focusing of X-rays generated by an X-ray generation device; the phase grating module comprises a first grating, a second grating and a third grating which are parallel to one another and have the same structure, thickness and grating period; the detector module comprises a scintillator, an imaging module and an image acquisition module, the scintillator receives Morie fringes with different frequencies, Morie fringe distribution images with different frequencies are formed through surface imaging of the scintillator, and the image acquisition module acquires Morie fringe images; and the processing module performs decomposition to obtain an absorption contrast image, a dark field contrast image and a differential phase contrast image. According to the method, the problems of low imaging sensitivity and th