There are many reasons why infants cry and do not sleep, generally due to the stimulation of external environmental factors and their own factors, in addition to systemic diseases such as infections, allergies, digestive system diseases, etc. can also lead to crying and sleeplessness. First of all, the infant’s own body development is not perfect, the cranial nerves are not yet mature, the rest time pattern has not yet formed, the external environment factors such as light, sound, temperature and humidity can lead to sleep instability, crying, this situation needs to pay attention to the changes in the surrounding environment, adjust the loose clothing and can be improved. Secondly, too much mental excitement or too much sleep during the day can also lead to restless sleep and crying at night. In addition, infants and toddlers can also be caused by their own factors, such as digestive discomfort caused by hunger and satiety disorders and physical discomfort caused by their own intimate clothing such as diapers. Again, such as micronutrient deficiency such as calcium deficiency, digestive system dysfunction can also be caused, in this case, it is necessary to visit the hospital to perform micronutrient and digestive system and other related tests to clarify the cause and guide the treatment. In short, there are many reasons why babies cry and do not sleep, so they must be dealt with in conjunction with the actual situation.