A three-year-old child’s old hand eating may be related to nutritional imbalance, bad habits, psychological factors, and can be treated by supplementing trace elements, distraction, psychological guidance, and so on. 1. Nutritional imbalance: Due to the rapid growth of three-year-olds, if coupled with the child’s partiality and picky eating, it may lead to nutritional imbalance, such as lack of calcium, zinc, etc., which may be manifested in three-year-olds eating hands and other symptoms. It is recommended to consult a doctor for a trace element test, and use calcium and zinc gluconate oral solution and other drugs to supplement trace elements under the guidance of the doctor. 2. Distraction: If a three-year-old child is bored, he may eat his hands, so he can take some toys or other games to distract the child’s attention and reduce hand eating. 3. Psychological factors: Some three-year-olds are timid or have low self-esteem and are reluctant to play with others, so they may eat their hands. Therefore, it is recommended that parents can encourage their children to build confidence, and if necessary, take the child to the hospital to do psychological assessment, and under the guidance of the doctor through verbal communication and other methods to do psychological counseling. Therefore, when a three-year-old child eats his hands, he should look for the cause of the disease first, and then deal with it accordingly.