Abstract: Aiming at the specific requirements of the precision lathe on the numerical control system, an open numerical control system scheme was proposed and implemented. This paper mainly discusses the overall scheme of the open CNC system of precision lathe, designs the FPGA hardware circuit, and studies the realization of various functions such as synchronous control, signal processing, communication and feedback adjustment of the servo motor in the open CNC system of the precision lathe. The method and simulation and experimental testing of each function. The cutting experiment results show that the system has high real-time performance, good synchronization, high processing precision and stable and reliable processing, and has certain application prospects.