The utility model provides a combination tool is maintained to drilling tool terminal surface, including the top -down salvage drilling rod, screw rod drilling tool, the junk mill that link together of screw thread formula in proper order, the screw rod drilling tool includes motor, shell, drive screw, and the motor outside sets up the shell, and the shell upper end is connected and is salvaged the drilling rod, installs in the lower part of the shell of motor and rights a section of thick bamboo, and drive screw connects the upper end motor output end, and the junk mill is connected to drivescrew lower extreme screw thread formula, the junk mill is located rights section of thick bamboo inside, rightting a lower extreme and being less than the junk mill lower extreme, it is the circularconical surface just to right a lower inner wall of the port. The utility model discloses can realize in the well the rightting and the centering of the drilling tool that drops, guarantee the workingface level of coping instrument simultaneously, the high -efficient accurate repairment of the drilling tool terminal surface of realizing dropping. The uneven problem of terminal surface coping thatleads to because of the bending of drilling rod pressurized has been eliminated.