Nonlinear effect seriously affects the signal transmission in optical fiber communication, resulting in signal distortion in waveform or spectrum. In order to overcome the nonlinear effect, Darboux transform is used to synthesize the information of the soliton signal at the transmitter, and the nonlinear Fourier transform is used to demodulate the eigenvalue recovery signal at the receiver. Through the improvement of the algorithm, the computational complexity of the nonlinear frequency division multiplexing (NFDM) communication system is reduced. The simulation results show that the NFDM communication system can effectively suppress the nonlinear effect.