There are many reasons why children cry at night, such as irregular work and rest, vitamin D deficiency rickets, or frightened, etc. Different reasons for different treatments, such as adjusting work and rest, vitamin D supplementation, timely appeasement and so on. 1. Irregular work and rest: the child’s sleep and rest is irregular, the child sleeps too much during the day, resulting in excessive nighttime excitement, and even crying and restlessness, so you need to adjust the child’s work and rest. 2. Vitamin D deficiency rickets: when the child suffers from vitamin D deficiency rickets, the child will show signs of excitation of the nervous system, excessive sweating, crying at night, occipital baldness, etc., you need to give your child calcium supplements as well as vitamin D in a timely manner, so that the child sunbathing more, and eat more calcium-rich foods, such as milk and so on. 3. Suffering from fright: when the child is frightened, the child will also cry at night, parents need to be timely soothing, sleep with the child at night, to give the child a sense of security, and should maintain a mild light at night, to create a relaxing and comfortable sleep environment for the child, and so on. If the above treatment does not work, parents can take the child to the hospital for psychological counseling. There may also be other reasons for children to cry at night, such as indigestion, etc. Parents can take their children to the hospital to find out the causes, and then carry out the relevant treatment under the guidance of the doctor.