The need for root canal treatment in children depends on the actual condition and the need for treatment. If a child’s tooth does not show indications for root canal treatment, it is important to preserve as much viable pulp tissue as possible. However, root canal treatment is usually required when a child’s milk tooth or permanent tooth with closed apical foramen has the following conditions: 1. Pulp disease: Pulp disease in milk teeth includes pulp inflammation and pulp necrosis, which may occur when a child’s milk tooth is cariously infected with pulp or is bumped by trauma. The treatment of pulp necrosis and irreducible pulpitis is mainly based on root canal treatment. 2. Periapical disease: When the periapical infection of milk teeth destroys the surrounding alveolar bone, it will lead to the resorption of the root part of the root canal infection, and then the residual root will be retained, and the eruption of permanent teeth will be too early or too late, which will also affect the order and position of the eruption of permanent teeth, and even cause Malocclusion. Chronic periapical infection in baby teeth may also cause the root tip to penetrate the gingival mucosa and expose it in the mouth, irritating the soft tissues and even forming traumatic ulcers. If pulpal or periapical disease develops in a baby tooth nearing replacement, extraction may be undertaken without root canal treatment. After completing root canal treatment it is also important to pay attention to oral hygiene and regular review, just like protecting normal teeth. It is important to protect the periodontium to prevent the tooth from loosening.