The invention relates to the technical field of
drill bit devices for
neurosurgery, in particular to a
drill bit device capable of suddenly stopping after drilling through a
skull, which comprises an output shaft, a
coupling head
assembly, a
coupling sleeve
assembly and a
drill bit
assembly, one end of the
coupling head component is spliced and assembled with the end part of an output shaft of the electric drill, the other end of the coupling head component is spliced and assembled with the coupling sleeve component, and the other end of the coupling sleeve component is sheathed and assembled with the
drill bit component; the connecting sleeve assembly comprises a connecting sleeve, an inverted conical hole, a first
steel ball, a through hole, a first compression spring, an inner sleeve and an ejector rod. An inverted conical hole is formed in the circumferential wall of the connecting sleeve in the circumferential direction, a first
steel ball is assembled in the inverted conical hole, and a penetrating hole is formed in the side wall of the right end of the connecting sleeve in the axial direction. When the
drill bit drills through the
skull, the axial and acting force of the
skull on the
drill bit disappears or is smaller than a certain value, under the action of an internal mechanism, the device does not transmit torque to the drill bit any more, the
cutting torque of the drill bit is automatically
cut off, and the purpose that the drill bit automatically stops after drilling through the skull without hurting other parts is achieved.