By testing the running gear system with fault, the vibration signals of gear system are acquired at different speeds. Using wavelet de-noising by threshold to extract the useful feature signals, combining time-frequency analysis with intelligence detection theory of wavelet analysis, the feature signals are decomposed into different frequency bands. Then, according to the energy feature theory, the magnitude of energy in each frequency band is calculated to identify different faults in different running conditions successfully. Based on above all, it called the MATLAB Script Node in LabVIEW to process and diagnose the acquired feature signals with fault. And, a gear fault detection system, Virtual Instrument Diagnostic System, is developed by combining both advantages of LabVIEW and MATLAB, using hybrid programming method about both of them. The system possesses various functions like as: collection, analysis, feature extracting, fault detecting, diagnosis and so on. The results show that the diagnosis system runs well and can be used in the detection and diagnosis of actual operation system.