Control valves are the crucial assembly, which controls the flow of medium in fluid machines. Control valves play an important role in electricity industry, nuclear industry, and chemical engineering. The technology of fault diagnosis is applied to the fault detection and fault diagnosis of the control valve with high flow rate for the sake of economic development and safety. This paper presents results of a study on classification and mechanism of the common faults of control valves in connection with the structure of the valve applied to the circle-electricity industry. We analyzed the principles and characteristics of different diagnosis methods, discussed the mechanism of different faults of the valve. Furthermore, we investigated the diagnosis method that is suitable for different faults of the valve and the pivotal technique with which intelligent fault diagnosis (IFD) can be realized successfully. In addition, the route and the plan of the study on IFD of the control valve with high flow rate is suggested to develop a system of intelligent fault diagnosis and detection (IFDD) for the control valve.