The main causes of lip biting in children include the following: first, the symptoms caused by children’s psychological tension, when children are very nervous, they often appear to involuntarily bite their lips, they need to give children more reassurance, so that after the psychological relaxation, the symptoms of lip biting will naturally be reduced. Secondly, symptoms caused by tic disorder in children may include lip biting, involuntary blinking and throat clearing, which can be treated with thiopride hydrochloride. In addition, due to bad habits, this symptom may occur if the child has bad habits of biting the lips, and the child needs to change the bad habits slowly.