A method for generating a Non-Linear Frequency Modulation NLFM, signal, comprising: determining a power spectral density according to a required Peak Side Lobe Ratio, PSLR; determining a frequency-time structures function of a signal according to the power spectral density; determining a time-frequency structures function of the signal according to the frequency-time structures function of the signal; integrating the time-frequency structures function of the signal to obtain a phase, and calculating discrete values of the signal using the obtained phase; and generating a series of digital signals according to the discrete values of the signal, and performing digital-to-analog conversion on the series of digital signals to obtain a NLFM signal, wherein integrating the time-frequency structures function of the signal to obtain the phase and calculating the discrete values of the signal using the obtained phase, and generating the series of digital signals according to the discrete values of the signal and performing digital-to-analog conversion on the series of digital signals to obtain the NLFM signal comprise: establishing an expression of the time-frequency structures function of the signal according to the number of polynomial coefficients and integrating the expression of the time-frequency structures function; substituting the polynomial coefficients into a result of the integration of the expression of the time-frequency structures function of the signal to obtain the phase of the signal which serves as a phase value of the signal at a waveform sampling point; substituting the phase value into an expression of the signal to obtain the discrete values of the signal; and generating the series of digital signals according to the discrete values of the signal, and performing digital-to-analog conversion on the series of digital signals to obtain the NLFM signal. determining a power spectral density according to a required Peak Side Lobe Ratio, PSLR; determining a frequency-time structures function of a signal according to the power spectral density; determining a time-frequency structures function of the signal according to the frequency-time structures function of the signal; integrating the time-frequency structures function of the signal to obtain a phase, and calculating discrete values of the signal using the obtained phase; and generating a series of digital signals according to the discrete values of the signal, and performing digital-to-analog conversion on the series of digital signals to obtain a NLFM signal, wherein integrating the time-frequency structures function of the signal to obtain the phase and calculating the discrete values of the signal using the obtained phase, and generating the series of digital signals according to the discrete values of the signal and performing digital-to-analog conversion on the series of digital signals to obtain the NLFM signal comprise: establishing an expression of the time-frequency structures function of the signal according to the number of polynomial coefficients and integrating the expression of the time-frequency structures function; substituting the polynomial coefficients into a result of the integration of the expression of the time-frequency structures function of the signal to obtain the phase of the signal which serves as a phase value of the signal at a waveform sampling point; substituting the phase value into an expression of the signal to obtain the discrete values of the signal; and generating the series of digital signals according to the discrete values of the signal, and performing digital-to-analog conversion on the series of digital signals to obtain the NLFM signal. establishing an expression of the time-frequency structures function of the signal according to the number of polynomial coefficients and integrating the expression of the time-frequency structures function; substituting the polynomial coefficients into a result of the integration of the expression of the time-frequency structures function of the signal to obtain the phase of the signal which serves as a phase value of the signal at a waveform sampling point; substituting the phase value into an expression of the signal to obtain the discrete values of the signal; and generating the series of digital signals according to the discrete values of the signal, and performing digital-to-analog conversion on the series of digital signals to obtain the NLFM signal.