Based on a fiber optical parametric loop mirror (OPLM) and a fiber Bragg grating (FBG), a scheme of 60 GHz optical millimeter-wave sub-carrier generation is analyzed and demonstrated. The conclusion indicates that OPLM can be used to achieve high-order harmonic and pump filter of photonic microwave signals at the same time, then optical millimeter-wave subcarrier can be obtained by leaving only the high harmonics. In the experimental demonstration, utilizing 5 GHz baseband signal, high-order harmonic generation and separation of the pump can be achieved by modulating the nonlinear and four-wave mixing and filtering in OPLM. Eventually, the required 60 GHz optical millimeter-wave sub-carrier signals can be realized successfully. Which shows good performance.