In 1999, Sofam introduced the second generation of discoscopic surgical system, METRX, with significantly increased magnification of the microscopic field of view, METRX technology has brought a new concept of microscopic discectomy, which is regarded as an important breakthrough in the field of minimally invasive and lumbo-scopic spinal surgery. The system can perform lumbar disc removal, laminectomy, lateral recess decompression and other procedures. It is suitable for herniated, prolapsed and free lumbar intervertebral discs, and can be used to solve lumbar spinal stenosis and nerve root canal stenosis with the help of auxiliary tools under the premise of skillful operation. Zhu Hongwei, Department of Functional Neurosurgery, Xuanwu Hospital of Capital Medical University, has the following main steps: Step 1: dilate the soft tissues to establish a working channel: dilate the longest muscle and multifidus interspace with a dilatation tube up to 22 mm, put the left/right piece of the dilatation tube of the appropriate length on the spreader bracket, and put the working channel formed by it outside the dilatation tube. (Figures 1,2) Step 2: Connect the free arm to the spreader bracket with the connector. There are 2 parts of the connector to the spreader bracket, which are selected according to the needs of the procedure. Step 3: Insert the guide beam, insert the guide beam into the hole from above the left/right blade of the dilatation tube and adjust it to the maintenance site. Step 4: Discoscopic removal of the nucleus pulposus tissue to achieve adequate decompression of the nerve root. Step 4 (alternative approach): microscopic removal of the herniated disc. The preference of microscopic surgery by national and international neurosurgeons is an important reason for the popularization of this approach. An auxiliary wrench is used to prop open the working channel, which is 50-55 mm in the upper part and 80-100 mm in the lower part. the disc is removed under direct vision and fixed under image guidance. Discoscopy was initially designed for the removal of simple disc herniations with a single segmental bias, and was not indicated for multi-segmental disc herniations with spinal stenosis. More than 70% of lumbar disc herniations have been reported in the literature as indications for this procedure. However, with the expansion of the indications for the procedure, the rate of excellence decreases. Discoscopy is contraindicated in patients with multisegmental stenosis, extensive epidural adhesions at reoperation, and lumbar structural instability. The advantages of discoscopy are: 1) Wide range of surgical indications. 2) Wide choice of implants. 3) No learning curve: helps surgeons to rapidly change from traditional open surgery to minimally invasive surgery.4) Minimally invasive: 1) Small soft tissue incision, 2 gap 3 vertebral body surgery maximal 5-5.5cm, open surgery needs 15-20cm. 2) Small damage to the structure of the bone tissues and most of the vertebral body’s posterior column structure is retained. 3) Small nerve interference.