One and a half year old baby sleep at night, there are a variety of factors, such as nutrient deficiency, environmental factors, gastrointestinal impact, etc., the treatment of the cause of the symptomatic treatment, such as timely supplementation of vitamin D and so on. The rapid growth and development of babies can easily lead to nutrient deficiencies, and the one that is more likely to be deficient is vitamin D. Vitamin D deficiency can lead to poor absorption of calcium, which in turn affects the nervous system, leading to a state of excitement that affects sleep. Vitamin D and calcium supplements should be taken under doctor’s supervision to alleviate the symptoms. The quilt is too thin, the light is too harsh, the surrounding environment is noisy are easy to cause the baby sleep is not solid, must ensure that the baby baby a comfortable sleep environment, clothing and quilt thin and thick appropriate, light dimming, keep quiet and so on. Babies eat too much too full or gastrointestinal dysfunction, also easy to cause sleep instability, if the problem occurs in a timely manner to improve feeding habits and probiotics under the guidance of a doctor (such as bacillus subtilis bacillus particles) to regulate the gastrointestinal tract, etc., to improve sleep. One and a half year old baby sleep at night 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, give targeted treatment or treatment.