Babies cry at night before bedtime mostly due to physiological factors, malnutrition, dietary factors or external stimuli. 1. Physiological factors, the baby may be physically tired before bedtime but not fully asleep, then it will be due to the irritability of the situation of crying or fussing. 2. Malnutrition, if the baby lacks vitamin D or calcium, it may lead to abnormal crying before bedtime. 3. Dietary factors, if the baby does not eat enough before going to bed and is in a hungry state, it will draw attention to itself by crying; or if it is fed too much, it will be stimulated by the gastrointestinal tract and suffer from indigestion, and it will also show signs of crying. 4. External stimuli, if the baby’s clothes and diapers irritate the baby’s skin, it will cry due to discomfort. Baby crying at night before bedtime may also have 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.