There are many dental diseases that can be viewed in dental films, the most common one that can be seen is the most commonly referred to as dental caries, which is also known as worm’s tooth, and the typical manifestation is the appearance of low-density images in the corresponding parts, enamel and dentin are shown as high-density images in dental films, once the decayed part appears, the corresponding part will be replaced by low-density images. In addition to caries, periapical periodontitis will also be reflected in the dental film, manifested as low-density transillumination image of the tooth corresponding to the apical part, and different periapical cysts and periapical granulomas will have different clinical manifestations. The periodontal membrane can also be viewed. If the periodontal membrane is widened, the same means that there is some problem with this tooth.