Babies sleep too little, may be insufficient breast milk, poor sleep environment, gastrointestinal dysfunction, vitamin D deficiency and so on. 1. Insufficient breast milk: the baby is in a hungry state, less sleep, easy to cry and wake up, most of the weight gain is slow. 2. Poor sleep environment: If the bedroom is noisy, light pollution, indoor heat and cold, bedding wrapped too tightly, may affect the quality of sleep, sleep time is reduced. 3. Gastrointestinal dysfunction: baby’s abdomen is cold, lactose intolerance, formula milk allergy, etc., gastrointestinal dysfunction appears bloating, abdominal pain, etc., will also affect sleep. 4. Vitamin D deficiency: the symptoms of the early stage of increased neural excitability, easily provoked, crying, sweating, etc., will also affect the quality of sleep. Infant sleep time is too little, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.