Abstract: A tire mold needs to drill holes on its inner conical surface, and it is difficult to process with general drilling machine or drilling and milling machining center. In this paper, a numerical control drilling machine for this process is developed. In this machine tool, the workpiece is placed on the worktable, and the rotation of the worktable realizes the workpiece indexing. Relative to the worktable, the drilling head can move along 3 coordinates. The y-axis direction is parallel to the inner cone bus, and the y-axis direction can be adjusted within a certain range to adapt to workpieces with different inner cone. The 3-coordinate displacement of the drilling head is driven by the servo motor, driven by the ball screw and guided by the linear guide rail, so the displacement is accurate and the positioning accuracy is high. The worktable, base and other main parts are cast, with good precision retention and strong rigidity. The machine has the advantages of high machining precision and convenient operation. The process parameters need to be optimized to further improve the processing efficiency.