Outer key groove machining tool

The utility model relates to the technical field of outer key groove machining, and provides an outer key groove machining tool which comprises a tool body used for containing a workpiece with an outer key groove to be machined, and a first clamp used for limiting the longitudinal movable range of the workpiece is arranged on the tool body. Second clamps for limiting the transverse movable range of the workpiece and limiting rotation of the workpiece are arranged on the two sides of the first clamp. A clamping part of a lathe is used for clamping a clamped block, a screw penetrates through an arc-shaped positioning groove to be connected with the lathe, the tool body is fully fixed, then the center of a workpiece needing to be machined with an outer key groove is aligned with a center hole and then placed at a workpiece groove, and after the area, needing to be machined with the outer key groove, of the workpiece is aligned with a milling cutter groove, the outer key groove is machined. According to the techn