A drill head locking device and a drill head are provided. The locking device comprises: a flange (1) having a through hole, and bearings (8) arranged on the inner wall of a small cylinder on the upside of the flange (1) and a supporting member (12) for supporting the bearings (8), a locking sleeve (2) also arranged over the flange (1), a first protrusion (5) arranged on the inner wall of the upper part of the locking sleeve (2) and a second protrusion (3) on the inner wall of the lower part. A spring (9) is arranged between the second protrusion (3) and an upper bottom surface (10) of the flange. A pressing plate (6) is threadedly connected on the outer wall (7) of the top part of the small cylinder on the flange and presses against the first protrusion (5). Holes of different sizes are arranged on the inner wall of the small cylinder in the corresponding positions to the second protrusion (3) and on the supporting member (12), thus forming a stepped-hole (11) which is arranged with steel balls (4) therein. By adopting such a locking device, the locking and loosening operations are easy and convenient to apply, providing a firm securing effect when in locking status with improved safety.
