Under normal conditions, the inner diameter of the cervical spinal canal (anteroposterior sagittal diameter and left and right transverse diameter) is of a certain size to accommodate the spinal cord nerves and other tissues in the spinal canal. However, if the inner diameter is smaller than normal, especially when the absolute value of the sagittal diameter is less than 12mm, it constitutes relative stenosis of the spinal canal, and when it is less than 10mm, it is absolute stenosis, which can cause a series of symptoms. The treatment of this disease is still mainly non-surgical, but those who have not been cured for a long time should still undergo surgery to expand the sagittal diameter of the spinal canal.