Lumbar traction is a rehabilitative and physiotherapeutic treatment for lumbar disc herniation in clinical practice. The principle is to use tension and counter tension to act on the lumbar spine. By pulling in the opposite direction, the purpose of treating lumbar disc herniation is achieved. Lumbar traction increases the lumbar spine gap, mainly defined in the lumbar 3, lumbar 4, lumbar 5 and sacral 1 gaps. According to the clinical research, the lumbar intervertebral space can be widened by a distance of about 2.5㎜ after the traction compared with that before the traction. With the widening of the intervertebral space, it can become negative pressure within it, and together with traction, the tension of the posterior longitudinal ligament between the vertebrae is conducive to the partial return of the herniated nucleus pulposus and the change of the nerve root irritation symptoms. Lumbar traction is a better clinical treatment for herniated discs.