T615K boring machine is the main equipment of our factory, which is the key equipment in the production of sugar machine, mill and crusher. We applied the PWM transistor pulse width speed control system to the T615K boring machine for the DC feed system of the machine's main shaft, column, headstock and radial tool holder, replacing the original Wuhan Heavy Machine Tool Plant with reference to the design of the former Soviet Union in the 1940s. , with the tube amplifier as the intermediate link of the magnetic expansion machine, generator, motor DC speed control system. Good results, is a new technology that can promote the application and practical.