Considering the problem that the optimization of NC machining parameters can only be done offline at home and abroad at present, the secondary development based on Huazhong numerical control (NC) 8 type highgrade numerical control system is carried out. A set of instruction domain scope module was completed, and realized machine data mining, analysis, process parameters optimization and other functions and the integration of computer numerical control (CNC) system to complete the machine processing status Electrocardiograph(ECG) realtime monitoring. The machining efficiency could be increased greatly by optimizing the feed rate by processing the load current through the instruction domain analysis. This method is easy to operate and has been widely verified in aerospace complex parts processing, and the machining efficiency can be increased by 30%~40%.