In this paper, a method of fault diagnosis of inverter power supply device based on SVM it to be studied and a kind of variable frequency power supply device simulating various fault states of Inverter power supply is to be designed. The voltage waveform of Inverter power supply in the normal state and in various fault states was measured and analyzed. The simulation experiment in Simulink of MATLAB was set up to testify the actual experiment. On the foundation of the analyzing of the output waveform and quality of the power, a method about fault diagnosing is put forward, i.e. the fault states of Inverter are classified using a method of fault diagnosing based on SVM. At last, the SVM method is validated accurate through experimenting.