The supercontinuum (SC) from 600 nm to 1500 nm is generated in the highly nonlinear photonic crystal fiber, pumped by acoustic-optic Q-switch pulses with a duration of 200 nm, a repetition rate of 3.3 kHz and tunable power. And the generation causes are also analysised. It is shown that when the pump wavelength overlaps with the zero- dispersion wavelength self-phase modulation and third-order dispersion plays an important role, the propagating pulses will oscillate. With the increasing of the peak power of pump pulse , the pectral width becomes wider.