The present invention discloses a vibration system of a loudspeaker, comprising a diaphragm and a voice coil attached to one side of the diaphragm, wherein the diaphragm comprises at least two layers of polyether-ether-ketone base films, and furthermore, the diaphragm comprises at least one layer of crystallized polyether-ether-ketone base film and at least one layer of non-crystallized polyether-ether-ketone base film. The diaphragm made of both crystallized and non-crystallized polyether-ether-ketone base films can have both an effectively improved acoustic performance and a lowered resonance frequency f0, thus, the acoustic effect of the loudspeaker can be improved.