Lumbar instability can be diagnosed by the following aspects: First, symptoms, the most common symptom of lumbar instability is lumbar pain, the patient often complains of lumbar pain like fracture, can be accompanied by symptoms of nerve pain in the lower limbs, when lumbar instability compresses the nerve roots, it can appear the symptoms of pain and numbness in the lower limbs. Secondly, physical examination, there can be percussion pain in the lumbar region during physical examination, and there can be limitation of movement during forward flexion and backward extension of the lumbar region. Thirdly, auxiliary examination can be performed to make the diagnosis. On the X-ray film, it can be seen that there is obvious misalignment of the lumbar spine, and there can be interruption of the continuity of the curve of the lumbar spine, and on the MRI, it can be seen that there is secondary spinal stenosis and image manifestation of nerve root compression.