The utility model discloses a numerical control roll grinder's automatic location driver plate that floats of headstock, the dabber can be followed axial displacement and set for apart from locate in the headstock, the dabber tip outside is located to the cover that the driver plate axial can remove, shifting block on the headstock can drive the driver plate rather than the synchronous revolution, roll axial terminal surface can tightly be supported in the top driver plate outside of stretching out on the dabber terminal surface, still be equipped with the elastic component, driver plate medial?surface and dabber terminal surface are tightly supported all the time to the both ends of elastic component elastic?expansion direction, the design has the block portion of matcing with the roll interface on the driver plate, still be equipped with drive arrangement, drive arrangement drives mobile core axle axial motion, the utility model discloses a scalable dabber makes elastic component production compression on top in the roll terminal surface, the headstock starts the back, thereby the rotatory drive driver plate of headstock shifting block is rotatory, and driver plate auto -eject under elastic component spring action links together with roll tip lock, and then realizes the drive of roll, the utility model discloses flexible operation, simple and convenient, labour saving and time saving.