Device for machining blind hole in bottom surface of deep-hole workpiece

The utility model relates to the field of machining, and provides a device for machining a blind hole in the bottom surface of a deep-hole workpiece, which comprises a guide post, a positioning key, a drill bit and a pull-back part, a first supporting part, a second supporting part and a third supporting part are sequentially and axially arranged on the diameter reducing part in the direction towards the large end of the guide column, a through guide channel is eccentrically formed in the guide column in the axial direction, a plurality of chip conveying grooves are evenly formed in the side, close to the guide channel, of the guide column in the axial direction, and a guide column positioning groove is formed in the other side of the guide column. The positioning key is assembled in the guide column positioning groove, a threaded hole is formed in the large end of the guide column, the pull-back part is fixedly connected with the threaded hole, and the drill bit is coaxially assembled in the guide channel. A