The invention discloses a millimeter wave signal photonics generating method based on a highly non-linear optical stimulated Brillouin scattering effect and a millimeter wave signal photonics generating device, and belongs to the technical field of microwave photonics. The device consists of a tunable laser, a first coupler, two parallel Mach - Zehnder modulator, a first DC power supply, the second DC power supply, the third DC power supply, isolators, second coupler, a first photo detector, spectrum analyzers, high nonlinear optical circulator, a second photo detector, microwave amplifiers, intensity modulator, a fourth DC power supply and a microwave signal source. The millimeter wave signal generating device according to the selected output frequency is highly nonlinear optical fiber different in 54GHz to 66GHz. Since the stimulated Brillouin frequency shift value and the wavelength of the pump light of relevant, also can adjust the wavelength tunable laser, millimeter wave signal generator output frequency of the device is adjustable within a certain range.