Baby always sleep not solid old wake up may environmental factors, bedtime excitement, such as vitamin D deficiency and other causes. 1. environmental factors: if the baby sleep environment is too noisy, will affect the baby sleep quality, resulting in the baby sleep always wake up, but also may be the sleep environment temperature is relatively low, the baby feel cold when sleeping, will also sleep. 2. Excitement before bedtime: If the baby is too excited before bedtime, such as playing games or being teased by adults, the cerebral cortex is still more excited after bedtime, which will lead to poor sleep. 3. Vitamin D deficiency: when the baby’s body lacks vitamin D, it is easy to cause increased neural excitability, which can lead to the symptoms of waking up at night and crying at night. Baby always sleep not solid old wake up may also be caused by other reasons, if the symptoms continue to be unrelieved, and the baby has other symptoms of discomfort, should be timely to the hospital, to identify the cause of targeted treatment.