The invention relates to a photo-generated millimeter wave noise generator, which comprises a chaotic laser, an erbium-doped fiber amplifier, a second polarization controller, a high nonlinear fiber (HNLF) and a high-speed photoelectric detector which are connected in sequence, wherein the chaotic laser is composed of a semiconductor laser, a first polarization controller, a 60: 40 optical fiber coupler, a variable optical attenuator and an optical fiber reflector. The scheme of the invention provides an optical generation technology of millimeter wave noise, the bottleneck of electronic bandwidth is broken through, the implementation scheme is simple in structure, and millimeter wave noise with larger bandwidth is easy to generate; according to the technical scheme, the power of millimeter wave noise output depends on the amplification power of the erbium-doped optical fiber amplifier; compared with a conventional electronic noise source, the output power of the electronic noise source is easy to adjust, and the maximum power capable of being output is larger; according to the technical scheme, millimeter wave noise is generated through the combined action of the nonlinear effect,dispersion and the like in the high nonlinear optical fiber, the frequency spectrum of the generated millimeter wave noise is flat, and the bandwidth is larger.