Radiographic testing is a non-destructive method that is used to detect macroscopic geometric defects inside the material. Radiographic testing uses the characteristics of X-ray and gamma ray (such as photosensitivity) to determine whether there are defects in the inspected material and workpiece through the observation of the attenuation change of X-ray or gamma ray on the radiographic film in the inspected material or workpiece, so as to evaluate its quality and use value without damaging the inspected material and workpiece.