Since 1934, when Mzxter and Barr reported on lumbar disc herniation and its surgical outcome, surgical treatment of lumbar disc herniation has occupied a very important place in spinal surgery. Traditional open surgery such as total laminectomy, hemi-laminectomy, and “laminotomy” disc nucleus pulposus removal is highly invasive, with incisions of 10 cm or more, and extensive stripping of the paravertebral muscles and occlusion of the lamina and part of the articular eminence, which destroy the posterior column structure of the spine and lead to lumbar instability and long-term lower back pain after surgery. Microendoscopic discectomy (MED) is one of the minimally invasive spinal procedures that have emerged in recent years, and is now widely used to resolve the patient’s disease while minimizing the damage to adjacent tissues, reducing trauma, and shortening the recovery period. Minimally invasive treatment of lumbar disc herniation has been developed for a short period of time, including percutaneous chemical nucleolysis in the 1960s, percutaneous puncture lumbar disc removal (PLD) in the 1970s, percutaneous endoscopic lumbar disc removal (AMD) in the late 1980s, and percutaneous laser disc decompression (PLDD) on the basis of percutaneous disc removal. However, each has its own drawbacks and contraindications, and the clinical results are not uniform and cannot be widely used. In 1997, the MED system was first introduced, allowing spine surgeons to effectively decompress lumbar nerve roots through a minimally invasive discoscopic approach. The surgical approach is the same posterior approach as that of traditional lumbar disc removal and microdiscectomy, with the endoscope and surgical instruments introduced directly through the 16 mm working tube to make a direct window in the ligamentum flavum and between the upper and lower laminae to remove the herniated disc tissue. The essence of the technique is the same as that of the posterior approach, except that direct vision is changed to observation on a monitor, and the operator can easily identify the various tissues and clearly understand the relationship between the dural sac, nerve roots and the herniated disc through the clearly magnified images on the surveillance system; The incision was reduced to about 16 mm, limiting the paraspinal muscle stripping to one side of the spinous process, not extensively stripping the paraspinal muscles, and only slightly biting the lower edge of the vertebral plate to widen the gap between the vertebral plates, completely preserving the structure of the middle and posterior columns of the spine, not interfering with the normal biomechanical structure of the spine, not affecting the stability of the lower lumbar spine after surgery, and reducing the incidence of postoperative spinal slippage, lower back pain and other complications; magnifying the operative field 64 times and providing a clear view on the monitor. The surgical field is magnified 64 times and the magnified field can be seen directly on the monitor, making the operation more accurate and precise. The original MED system had limitations, including the inability to reuse the endoscope, distorted images, and a small working tube that limited operation. The 2nd generation discoscopy system, the METRx system, has remedied these deficiencies. The METRx system has more advantages than the 1st generation MED system, including improved image quality, reduced endoscope diameter, a variety of working tube models, more operating space in the operating tube, and reduced cost per procedure. Improvements in optics and working tube space have made the procedure easier and safer. Unlike percutaneous minimally invasive surgery, the METRx system allows the operator to manage occult disc rupture fragments and lateral saphenous stenosis in addition to limited disc herniation. This is why it is so widely used.