There is a wide range of degenerative diseases of the lumbar spine, including lumbar disc herniation, lumbar stenosis, lumbar spine instability, and lumbar spondylolisthesis. Traditionally, the surgeries have been open, i.e., from a posterior lateral incision (OTLIF). As there are many disadvantages of OTILF, including: 1. Traditional open surgery requires extensive stripping of bilateral paravertebral soft tissues, which is traumatic, bleeding, and often leads to muscle denervation and atrophy. 2, Due to the removal of bilateral vertebral plates, spinous processes and their ligaments, there is a great deal of damage to the posterior lumbar spine structures, which also tends to cause adhesions to the dura mater and nerve roots after surgery. For these reasons, minimally invasive surgery (MIS-TLIF) has been developed. Traditional surgery usually requires more than 10cm of incision to complete the surgery, while minimally invasive surgery requires about 4cm to complete the surgery. It has the following advantages: 1. The whole procedure is performed with the help of an expandable and open working channel, which can be expanded both at the bottom and top, and can be opened both vertically and horizontally, providing a wider access to reach the surgical area accurately. 2. 2.No need for additional endoscopy, all done under direct vision, no need for hand-eye separation training, not much different from the conventional TLIF surgical technique, short learning curve for surgical operation, easy to master the technique. 3.By bluntly separating the multifidus muscle bundle, or directly entering through the gap between the multifidus muscle and the longest muscle, and establishing the surgical field of view through the canal retractor, it avoids extensive stripping of the paravertebral soft tissues. 4.Placing the dilatation cannulae step by step from small to large, the muscle fibers are gradually pushed apart, and the order of muscle arrangement will not be changed. Due to the avoidance of violent operation, the intraoperative muscle pressure is lowered, the degree of muscle injury is reduced, the postoperative scar tissue is reduced, and the physiological function of the paravertebral soft tissues is effectively preserved, which reduces the incidence of postoperative low back pain. 5.Since the pulling force on the muscles is evenly distributed around the expander, the abnormal load on the local muscles exerted by the traditional application of the vertebral pulling hook pulling is reduced, thus reducing the incidence of atrophic degeneration of the paravertebral muscles. 6. Fan Shunwu et al. compared the damage to the paravertebral muscles of the above two surgical procedures and found that the postoperative muscle phosphokinase level of the minimally invasive group was significantly lower than that of the open group, and the VAS score and ODI score of the minimally invasive group were significantly better than those of the open group at 1 year after surgery. Our experience: We have completed more than 100 MIS-TLIF surgeries, with good surgical results and no case of intraoperative conversion to open surgery. 1, the operation time was 80min-150min, average 100min, which was comparable to the open surgery group. Bleeding volume was 50ml-150ml, with an average of 110ml, which was significantly less than that of the open surgery group. 2, after removing the drainage tube after surgery, all patients walked on the ground at an early stage under the protection of waist circumference, without complaining of lumbago and other discomforts, which was significantly better than the open surgery group.