Male patient, 44 years old, was admitted to the hospital with “low back pain with radiating pain and numbness in the left lower extremity for more than 1 month”. He was admitted to the orthopedic department: hypoesthesia of the skin of the anterolateral left calf and dorsalis pedis, grade 4 strength of the left bunion, straight leg raising test of the left lower limb (+), Kirschner’s sign (+), normal knee tendon reflexes bilaterally, disappearance of Achilles tendon reflex, and no pathological reflexes were elicited. CT showed: lumbar 4/5 disc herniation. The patient was given “posterior lumbar 4 and 5 discectomy + unilateral lumbar 4 and 5 internal fixation with arch nail + intervertebral fusion” under combined lumbar rigid anesthesia, after which the patient’s symptoms disappeared, and the next day the patient was given functional exercise under the protection of lumbar girth. The characteristics of the treatment of this case: (1) small surgical incision; (2) unilateral exposure, the use of unilateral arch nail fixation micro-innovation technology to achieve the purpose of solving the lumbar instability, greatly reducing tissue trauma, significantly shorten the operating time, less bleeding, postoperative patient recovery, and greatly reduce the cost of treatment.