Many babies in infancy have nail biting, which in itself is not a major problem and usually goes away when they grow up, but if it persists it needs to be brought to the attention of parents. Always biting nails is a common childhood behavior problem, and the occurrence of childhood behavior problems is importantly related to parental expectations, parenting style, parental culture, and learning environment. Everyone always has some anxiety or restlessness, and adults can relieve it in a variety of ways, but also children have fewer resources at their disposal, and what they have at their disposal is mainly their own bodies, so nail biting, lip biting, etc. becomes the most convenient and quick way. Generally speaking, children bite their nails is emotional tension, emotional needs are not met and produced, parents should be more love and care, eliminate their depression and loneliness, in the discovery of children biting their nails, should be distracted to other things, encourage children to build confidence in correcting bad habits. Scolding and sarcasm or smearing bitter medicine on the finger are counterproductive and aggravate the child’s emotions. If parents are sensitive and attentive enough to fully understand their children, they should be able to find the cause of these habits and address it promptly when the child initially has them. Even if the cause cannot be found for a while, parents should at least observe closely and take the initiative to lead their children to do some fun activities to enrich their lives and make them more relaxed.