Clinical studies have shown that the change in the physiological curvature of the lumbar spine is the result of imbalance in the mechanical structure of the lumbar spine due to degeneration, which directly mediates the occurrence of lumbar disc herniation; at the same time, the mechanical structure of the lumbar spine will be further disturbed after lumbar disc herniation, which aggravates the reduction or straightening of the physiological curvature of the lumbar spine, and even the occurrence of kyphosis or scoliosis. The pelvis is the base of the lumbar spine, and the sacroiliac joint is an important component of the pelvis, while pelvic rotation and sacroiliac joint misalignment lead to long and short legs and claudication, resulting in straightening of the physiological curvature of the lumbar spine, scoliosis, lumbar spine functional degeneration, and finally lumbar disc herniation. Thus, we believe that there is a correlation between sacroiliac joint misalignment and lumbar disc herniation. On the other hand, patients with protective postural changes to alleviate the symptoms of lumbar pain aggravate the reduction or straightening of the physiological anterior convexity of the lumbar spine, or even the retroflexion or lateral curvature. The degeneration of the lumbar disc inevitably affects the overall mechanical stability of the lumbar spine, causing disorders or secondary compensations in the structural balance of the lumbar spine. The reduction or straightening of the lumbar curvature causes changes in the normal anterior width of the lumbar spine gap, or even the anterior narrowing and posterior widening, and increases the pressure on the posterior fibrous ring and posterior longitudinal ligament by the posterior displacement of the nucleus pulposus. It also further affects the balance of the forces on the left and right sides of the pelvis, and the direction of the combined forces acting on the pelvis by the lumbar vertebrae is changed, and the direction of the combined forces acting on the lumbar vertebrae by the pelvis is also changed in order to maintain the mechanical balance, and the forces on both lower limbs acting on the sacrum by means of the iliac bone are changed, and the forces on both sides are unequal, which aggravates the degree of misalignment of the diseased sacroiliac joint. In clinical practice, if the traction or pushing method is inappropriate, some patients cause sacroiliac joint injury and dislocation in the process of treating lumbar disc herniation. From the other side, lumbar disc herniation is correlated with sacroiliac joint injury and subluxation.