The invention discloses a broadband noise signal generator and a signal generation method thereof. The generator comprises a super-radiation light-emitting diode, a filter, an optical amplifier, an optical attenuator and a single-row carrier photoelectric detector; the super-radiation light emitting diode outputs an amplified spontaneous radiation optical signal; the amplified spontaneous emissionoptical signal is input to the filter for filtering; the filter outputs a narrow linewidth optical signal with a preset wavelength range; the narrow-linewidth optical signal is input into the opticalamplifier for amplification and then input to the optical attenuator; and the optical attenuator controls the power of the optical signal, and an optical signal output optical attenuator is input tothe single-row carrier photoelectric detector for spectrum and electric spectrum conversion so as to output a broadband electric noise signal. The broadband noise signal generator is simple in structure and small in overall size, refrigeration is not needed, and the problem that an existing noise generator is difficult to meet the requirement for power needed by existing radar, communication devices and the like is solved.