Drill bit drilling depth adjusting device

The utility model relates to a drill bit drilling depth adjusting device which comprises a sleeve body, a thread adjusting sleeve, a locking nut and a fastening screw. The sleeve body is used for being arranged on a drill bit in a sleeving mode. A screw hole penetrating through the side wall of the sleeve body is formed in one end of the sleeve body. The fastening screws are matched with the screwholes and are used for fixedly clamping the sleeve main body on the drill bit; internal threads are arranged at the other end of the sleeve main body, the threaded adjusting sleeve is slidably arranged on the drill bit in a sleeving mode, and one end of the threaded adjusting sleeve is in threaded connection with the sleeve main body and can be screwed into the sleeve main body; and the locking nut is in threaded connection with the threaded adjusting sleeve, can move in the axial direction of the threaded adjusting sleeve and is in contact with the sleeve main body to limit the axial movement of the threaded adjusti