An exposure apparatus for a paraspinal muscle clearance approach with a posterior spinal small incision includes a spinous process side vertebral plate retractor and a cooperating vertebral arch outer side retractor. The apparatus can be used to separate a clearance between a multifidus muscle and a longissimus muscle under direct view, easily and atraumatically reach a screw fixation position on a vertebral arch pedicle, expose a facet joint, bluntly separate the multifidus muscle from the vertebral arch, accurately place the retractors, and thereafter locally form a surgical operation tunnel space that externally extends 10 degrees to 15 degrees. A design of angles and structures of retractors effectively protects local soft tissues and prevents a tissue damage while executing traction on local muscles and ensuring an adequate surgical space.