Soliton pulse compression based on dispersion decreasing fiber (DDF) with increasing nonlinearity is proved according to the theoretical deduction. Some characteristics of compressed pulse such as compression factor and pedestal energy are analyzed through the symmetrized split-step Fourier method. It is found that the final compression ratio achieved by a nonlinearity increasing fiber is the highest while the ratio achieved by a dispersion decreasing fiber is actually the smallest. Through comparing with dispersion decreasing method, the results show that almost the same compression ratio and lower pedestal energy can be achieved with half of the original fiber length by nonlinearity increasing method.