The main reasons for the splitting of teeth after root canal treatment are as follows: the tooth has a large defect due to caries and other reasons, and the treatment requires full removal of decay, so the remaining thin wall is very easy to split; the nutritional supply of the tooth mainly comes from the pulp, and the tooth after root canal treatment is killed and taken out, so the tooth without nutritional supply becomes fragile and may split even if it eats normal food. Therefore, it is best to get a crown restoration immediately after root canal treatment, which means that the treated tooth will be covered with a metal or porcelain crown to avoid tooth splitting. If tooth splitting has already occurred, we should do different treatment according to the site, degree and time of splitting, as follows: 1, if splitting has just occurred, very individual tooth tip or small part of the tooth splitting, most of the remaining teeth are stable, no biting pain, no apical lesions on dental films, the splitting activity can be extracted, and then do crown restoration; 2, if the splitting wall is deeper, or the remaining tooth activity is more obvious, and then coupled with symptoms such as swelling and pain, it is generally necessary to extract. Three months after extraction, implant denture, removable denture or fixed denture restoration can be chosen according to the indications.