Numerical simulation indicates that a Mach-Zehnder Interferometer（MZI） constructed from the Dispersion-Decreasing Fiber（DDF） can not only compress higher-order soliton

but also effectively suppress the pedestal after pulse compression.Studies indicate that high-quality pulses can be obtained by flexible adjustment of the two arms of the interferometer and the power split ratio range of the coupler that enable the interferometer to have good compression property is obtained

which has a certain guiding significance to the choice of the parameters in experiments.It is also found in the studies that high quality pulses can still be generated even when fairly large input-to-output dispersion ratio is chosen.