The invention discloses an application method of a special follow rest for turning a slender shaft. The application method comprises the following steps: a follow rest is fixed on a turning machine tool post (7); and a support bolt (1) is adjusted to contact with a lathe slide carriage (8). Three grooves are formed in a frame body (5); after a slide plate (6) is adjusted in the radial direction along the grooves, the slide plate (6) is fixed by a screw; a turning tool (3) is vertically fixed on the frame body (5) by a screw (4); and the radial turning force is mainly born by the slide carriage in turning. A workpiece is stabilized by three support bearings (2) without vibrating. The application method enables the turning to become stable, and is high in machining quality.