This invention discloses a trans-vertebral and intra-vertebral plate and a rectangular cage with a slot for the plate of spinal fixation device, for neutralizing intervertebral movement for the spinal interbody fusion. The rectangular cage with a vertical or oblique slot is inserted into the intervertebral space from the lateral or anterior side of the spinal column and then the plate is inserted through the slot of the cage and hammered into and buried inside two adjacent vertebral bodies, to achieve three-dimensional intervertebral fixation.
