The utility model discloses a flow limiting control valve and a pressure reducing device control structure. The flow limiting control valve is mainly composed of a valve body, a diaphragm, a spring, a valve seat, a valve rod, a connector, a transmission plate, etc., and the elements are organically combined. The pressure reducing device control structure comprises a vacuum drawing device, a pneumatic valve, a flow limiting control valve, a pressure reducing device outlet pipe line and an air complementing pipe line, wherein the pressure reducing device outlet pipe line is communicated with the air complementing pipe line and connected with the vacuum drawing device; the gas complementing pipe line is provided with the flow limiting control valve and the pneumatic valve. The utility model is a safety protective device; when a pressure reducing device works normally, compression wind stops abruptly air supply, a negative pressure regulating valve controlled by the compression wind can not work normally, and the flow limiting control valve can prevent a great deal of air from entering the pressure reducing device; when the compression wind stops air supply, the pressure reducing device can normally work and run. The flow limiting control valve has the advantages of simple structure, convenient operation and reliable performance, and can be used for controlling various pressure reducing devices.