Children always bite their fingers is a common clinical symptom, the main reasons are the following: 1, lack of security, 3-6-year-old babies are introverted, especially where there are many people, the baby nervous will lack security, there will be finger biting phenomenon, this situation parents must not scold, need to give the baby love, and actively educate the baby to develop good habits; 2, the lack of trace elements, the baby Micronutrient deficiency, such as iron deficiency, zinc deficiency, prone to this nail biting fetish, the baby is often accompanied by a lack of love to eat, slow growth and development, this situation suggests that parents promptly take the baby to the hospital pediatrician to check the micronutrients; 3, the baby imitates the actions of others, the baby is in the age of curiosity about external things, easy to imitate the actions of others, parents in this case to strengthen supervision, to create a good growing environment for the baby.