The main purpose of wearing a crown is to repair decayed and defective teeth, restore the chewing function of teeth and achieve aesthetic effect. Before wearing a crown, the affected tooth needs to be treated, the decayed tooth needs to be filled with decaying resin, if there is pulpitis, root canal treatment should be done first, and wedge-shaped defect should be filled first, if the crown is worn without treatment, it will be more troublesome and not easy to observe if the tooth becomes diseased in the future. Then, a model of the entire tooth is taken and a plaster model is poured out and sent to the manufacturer, and the patient first wears a temporary crown to protect the tooth. At a later stage, the manufacturer makes a crown for the tooth to be worn according to the type and color of the crown material chosen by the patient. When the patient visits again, the doctor first protects the other teeth with a rubber barrier to block saliva, and then treats the affected tooth by etching the surface with an acid etchant, rinsing and blowing it dry. The tooth surface and the inner side of the crown are coated with bonding agent, and then the tooth is quickly put on for fixation, adjusted to the proper position after light curing, and finally jaw adjustment, and the crown fitting is completed, and after wearing the crown, care is taken not to bite hard objects so that the crown does not strain the porcelain.