this is a medical instrument, wear between the costal margin and hipbone. under the conditions of lying,through dynamic decompression will the gap of waist intervertebral disc bigger. to restore the height of the intervertebral disc. form a negative pressure within the intervertebral disc, to reset the vertebral nuclear, back, and remove of nerve root compression, relieve symptoms. after when the body upright, by supporting the waist in no-load condition, ensure that no longer highlight of nucleus pulposus,provide fiber ring healing with enough time and space, make the fiber ring fixed. but also in sit, stand, line under different positions such as treatment, do not delay the normal work and life.