Thoracic spinal stenosis mainly consists of two diseases: ossification of the ligamentum flavum and herniation (calcification) of the thoracic intervertebral disc, and some patients have both ligamentum flavum and herniation of the thoracic intervertebral disc, and the main problem of this disease is unilateral lower limb or both lower limbs weakness, stiffness, and the sensation of stepping on cotton, and some of them may have urinary or faecal disorders. The only treatment for thoracic spinal stenosis is surgery, but the risk of surgery is greater than that of both lumbar and cervical spine, and so many renowned specialists are reluctant to perform such a surgery. However, we have accumulated some experience, and we have intraoperative monitoring with a neuromonitor, which greatly improves the safety of the surgery.