Abstract: In this paper, according to process characteristics of the Ultra-precision single-point diamond fly cutting machine tool, the structure of "IPC+Bus+Servo Driver" is adopted to realize X-axis/spindle motion control, and through the OPC communication between IPC and Siemens PLC, the logical control and intelligent state monitoring of the fly-cutting machine tool are realized. The function of the new structure control system is combed. Based on Qt5.9 platform, the development of Human-machine Interface for fly-cutting machine tool is completed. After a long process test, the software and hardware of the machine tool measurement and control system run well, and the control system has stable performance. The processing roughness of KDP crystal reaches 1.173 nm, and the processing PV value of large-caliber aluminium parts is better than 3 μm.