Children always bite their nails, according to different reasons to give disposal, as follows: 1, lack of trace elements, such as lack of zinc or iron can lead to the phenomenon of baby nail biting, should go to the hospital to perform trace element testing, according to the results of zinc or iron supplementation treatment. At the same time, attention should be paid to the baby’s diet with more food containing iron and zinc; 2, psychological problems, because the child’s internal anxiety, emotional tension, lack of security, or emotional needs are not met and a bad habit. Parents should care more about their children, eliminate the inner insecurity, do a good job of psychological guidance, communicate with the child, guide the child to say the heart of the trouble, nail biting to distract, can accompany the child to play games or let some chores, etc., so that the child’s attention to other aspects, do not reprimand the child, nail biting should be praised in a timely manner after the situation improves, give encouragement, slowly change the habit of nail biting.