A radiography diagnosis device includes a casing having an opening, a first shielding structure, a dose measuring unit, a transmission-type X-ray source module, and an image receiving assembly. The first shielding structure is disposed in the casing and forms a shielded space located between the transmission-type X-ray source module and the image receiving assembly and corresponding to the opening. An object to be detected is adapted to enter the shielded space through the opening. The transmission-type X-ray source module is disposed in the casing and adapted to provide an X-ray toward the object to be detected in the shielded space. The image receiving assembly is disposed in the casing. During image capturing, the X-ray generated by the transmission-type X-ray source module is received by the dose measuring unit, and the image receiving assembly receives the X-ray passing through the object to be detected at the same time.