Abstract: To study the method of designing nonlinear frequency modulation (NLFM) signal waveform, the dynamic selection method was adopted on the basis of phase stationary theory. The more applicable NLFM signal waveform could be designed with this method according to the concrete requirements of peak sidelobe level and mainlobe width of the output waveform of the pulse compression system, and the flexibility of waveform designing was increased, and operating times was decreased. The NLFM designed with this modified method has low peak sidelobe level. Some designing examples were shown. The validity of this modified method is confirmed by simulation results.