Abstract:The object of this study is large computer numercial control (CNC) crankshaft grinder, heavy roll grinder and heavy duty CNC boring and milling machine used for nuclear power equipment manufacturing. Signal acquisition, fault diagnosis, and early warning technology were studied for key parts of these equipments. The instrument used for field monitoring and fault diagnosis was developed, and fault diagnosis knowledge base was established for them. Then the computer numerical control (CNC) machine tool fault early warning and diagnosis model and CNC machine tool fault early warning and diagnosis platform was developed. It implements the following functions: the status can be displayed, the fault can be diagnosed, the performance can be predicted for CNC roll grinder, CNC crankshaft grinding machine and Heavy duty CNC boring and milling machine, and etc.