The following steps are required for the preparation of the tooth after root canal treatment: First, the tooth is prepared by grinding away a certain amount of the tooth with a lathing needle to prepare the standard shape of the tooth, and at the same time, a uniform and continuous shoulder is prepared to connect closely with the crown at a later stage. Secondly, the gingival row is performed for the subgingival abutment, and the gingival row can make the abutment clearer for later impressions. Thirdly, the impressions are taken, which are currently made of silicone rubber, so that the shape of the tooth can be completely reflected and the posterior dentition can be more precise. Fourth, the colorimetric process is carried out to compare the color of the teeth. Fifth, the temporary tooth is made, then the patient can go home and wait for a week or so, the crown will be completely made, and then the patient can wear the tooth.