A ray calibration device comprises a driving component (1), a cam component (2), and a calibration component (3). The calibration component (3) is located below the cam component (2). The driving component (1) is used for driving the cam component (2) to rotate. The cam component (2) is used for applying a pressure to the calibration component (3), so that the calibration component (3) downwards moves into a ray region. The present invention also comprises a working method for the ray calibration device, a radiation imaging system and a working method therefor, which relate to the technical field of radiation imaging and can resolve the problems of low calibration efficiency and large required space of the existing calibration device.
