Four-year-old children always wet the bed in the middle of the night without waking up may be related to physiological factors such as drinking too much water before going to bed, fatigue and so on, but also may be related to pathological factors such as enuresis, cystitis, central nervous system abnormality and so on, need to combine the cause of the general treatment, medication and so on. 1. Physiological factors: If you drink too much water before going to bed, or consume fruits with more water, or due to too much excitement during the daytime play, it may lead to the situation that a four-year-old child always wakes up in the middle of the night and wets the bed, which can be improved by improving the living and dietary habits, and so on, to improve the symptoms. 2. Pathological factors (1) enuresis: it often shows that sleep is too heavy, difficult to wake up, and the child wakes up after wetting himself, which may lead to four-year-old children always wetting the bed in the middle of the night without waking up. It is recommended to give psychological guidance, dietary adjustments, awakening training, etc., and follow the doctor’s instructions to give desmopressin. (2) cystitis: frequent urination, urinary urgency, urinary pain, etc., may lead to four-year-old children do not wake up in the middle of the night always wet the bed. For bacterial cystitis give cefazoxime, ceftriaxone and so on. Four-year-old children do not wake up in the middle of the night always wet the bed may also be related to other causes, it is recommended to seek timely medical treatment in order to clarify the cause of the disease and standardize the cause of the disease. The use of drugs need to follow the doctor’s instructions, do not unauthorized use of drugs.