Theoretical analysis on the femtosecond pulse generation system is presented. The finite gain bandwidth of the ytterbium-doped fiber amplifier limits the performance of pulse compression by distorting both the chirp and pulse shape. To generate additional bandwidth whilst retaining the desired linearly-chirped similariton characteristics, the amplified parabolic pulses are injected into highly-nonlinear fiber (HNLF). The compression efficiency and pulse duration of compressed pulse are investigated for different parameters of HNLF. The quantitative analysis shows that lower group-velocity dispersion (GVD) is preferable; higher nonlinearity parameter can lead to more short minimum pulse duration of compressed pulse, however, the compression efficiency decays more rapidly with increasing HNLF length. The shorter compressed pulse can be obtained through increasing the length of HNLF in a certain range, meanwhile, the compression efficiency must be taken into account.