The invention discloses a tool for maintaining a needling point of a sacroiliac screw guide needle and regulating direction. The tool comprises a
grinding drill, a sleeve, a sleeve fixer and
a diamond point bit, wherein a working surface of a
drill bit at the lower end of a
grinding drill rod is an arc surface; the
diamond point bit is inserted into a guide needle passage in the center of the
grinding drill; a fixing wing clamp arranged on the drill rod of the grinding drill is locked into a locking slot in the drill rod of the grinding drill; the drill tip extends out of the
drill bit of the grinding drill; the sleeve consists of two semicircular cylinders; the upper end of the sleeve is connected to the lower end of the sleeve fixer by screw threads; the center of the sleeve fixer is provided with a
pipe cavity through which the drill rod of the grinding drill can pass; a fixing bolt is arranged on the wall of the
pipe cavity and is used for fixing the sleeve on the drill rod of the grinding drill. The tool disclosed by the invention integrates the functions of maintaining the needling point of the screw guide needle and regulating the direction of the guide needle; a power drill is used for driving the grinding drill and the
diamond point bit to rotate; an arc-surface opening is drilled in an
iliac bone outer plate, and then the sleeve fixer, the sleeve and the
diamond point bit are taken down; the directions of the drill rod of the grinding drill and the guide needle passage are regulated by motion of the
drill bit of the grinding drill in the arc-surface opening.