A millimeter-wave noise generation scheme is proposed in this paper. The scheme is based on a monolithically integrated dual-mode chaotic laser, which consists of a distributed Bragg feedback (DFB) section, a phase section, and an optical amplification section. The output spectrum state of the dual-mode laser can be controlled by adjusting the injection current in the three regions. The monolithically integrated dual-mode chaotic laser has stable chaotic output and can be used as a light source for integrated millimeter-wave noise source. As a feasibility demonstration, a dual-mode chaotic laser with a mode interval of 2.05 nm was generated in the experiment, the optical mixing on a photodetector produced millimeter-wave noise with a center frequency of 259 GHz and a bandwidth of 44 GHz (237–281 GHz), achieving a typical value of excess noise ratio of 47 dB. It has the advantages of high noise source utilization, small noise source volume, and high integration.