The invention discloses an electrical fast transient burst generator. The generator comprises a power supply system, a keyboard unit, a display unit, a main control unit, a high voltage power supply, an energy storage capacitor, a main capacitor, a frequency generating circuit, a main switch, a waveform loop and a coupling and decoupling circuit, wherein the main control unit controls the high voltage power supply to reaches a set voltage so as to charge the energy storage capacitor; the energy storage capacitor charges the main capacitor through a charging loop; the main control unit generates a corresponding control signal to control the on or off of the main switch according to a set frequency; when the main switch is turned on, the main capacitor forms an interference waveform through the waveform loop; when the main switch is turned off, the energy storage capacitor provides energy for the main capacitor for charging; the frequency generating circuit is used for generating a PWM signal for the main switch; and when the switch is controlled by the PWM signals with different frequencies generated by the main control unit and the frequency generating circuit, electrical fast transient waveforms with different frequencies are generated by switching the different frequencies. The anti-interference capacity of the generator per se is improved.