The vibration characteristics of power capacitor are studied by way of experimental modal analysis（EMA）.A set of EMA testing system is set up in the test laboratory to test the capacitor by adopting three different kinds of excitation modes respectively.It is shown by the modal parameters that the testing result excited by sine sweep and white noise is more accurate than that by impulse excitation.The excitation mode of the test is

on the one hand

normalized and

on the other hand

each main modal parameters of capacitor is obtained

which provides a reference for low vibration and noise design of capacitor.