Abstract: The coupling sleeve is an important part of the rock drill tools for non coal mine.The thread processing quality of the coupling sleeve is directly related to the service life of the coupling sleeve.The whirlwind milling is a high speed milling screw device matching with the common lathe.Because of its high velocity，high precision，good surface roughness and so on，it has been paid more and more attention in the industry.The modification methods of the slide plate，the ball screw，the wheel box，the cutter bar and the milling axle box on the ordinary lathe are introduced.At the same time，a brief introduction to the control circuit design of SIEMENS S7-200 series PLC for controlling the main components，including SIEMENS MM440 inverter，stepper motor，main motor and other electrical components，is also presented.Finally，the modification of the ordinary lathe to the whirlwind milling machine with inner thread for rock drilling coupling sleeve corrugated is realized，which solves the problem of the inner thread machining of drilling coupling sleeve.

Key words: Coupling sleeve, Whirlwind milling, Clutch, Ball screw, Wheel box, Milling axle box