An all fiberized novel subns pulsed fiber laser was presented based on the “figureofeight” cavity modelocking. The output pulse train was directed to pass a fiberized acoustooptic modulator based on firstorder diffraction to reduce the pulse repetition rate from 2.78 MHz to 93 kHz by adjustable pulse picking. After the repetition rate decreasing, the peak power of the pulse laser was over 25 kW with the second amplifier, of which slope efficiency was 68.1%. Then the laser was used to excite bismuth doped silica fiber with optimization fiber length of 3m for supercontinuum generation. Finally the obtained laser spanned a spectral range of 1 100~2 200 nm with flatness better than 3 dB.