The background and significance of the research on optical generation technology of millimeter-wave are introduced. Several mainstream optical generation technologies of millimeter-wave are reviewed, including direct-modulation, external-modulation and optical heterodyne; the improved methods are also summarized, including a novel scheme for optical millimeter-wave generation based on double-sideband modulation, and a new double-uniform fiber grating millimeter-wave generator and so on. In addition, two novel optical generation technologies of millimeter-wave are reviewed, including a method to realize millimeter-wave subcarrier optical signal generation by using a double wavelength optical spectrum of a certain distance with fiber grating filter and optical frequency multiplication.