The root fracture of milk teeth is divided into apical 1/3 fracture, mid-root 1/3 fracture and supra-root 1/3 fracture, and the treatment methods are as follows: 1. For supra-root 1/3 fracture, the crown of the milk tooth is relatively loose and generally difficult to heal, so in the case of supra-root 1/3 fracture, the crown of the milk tooth is usually extracted and the remaining root is treated at the same time; 2. For mid-root 1/3 fracture, the milk tooth is fixed if the milk tooth is loose. Generally fixed for 2-3 weeks and then examined by radiographs to observe the root development; 3, apical 1/3 fracture, the tooth does not look too abnormal from the outside and generally does not need any treatment, but it should be checked regularly. Because after the root fracture, internal resorption and inflammatory resorption may occur, so regular checkups are needed to deal with new problems in time.