A radio over fiber (ROF) system is a product of the broad band and wireless in the communication industry. It combines the optical fiber communication technology and millimeter-wave communication technology, and has a broad application prospect. At present many countries mark off unlicensed continuous-frequency spectra in 60 GHz millimeter wave frequency band, which makes 60 GHz millimeter-wave wireless communication become one of the hot researches in the field of close wireless communication. In order to reduce the cost of a ROF system and improve its performance, an improved 60 GHz millimeter-wave generator based on feed-forward modulation (FFM) technique is proposed. The principle of the photoelectric device is analysed and the effect of different parameters setting in the performance of the system curve is simulated. The scheme combines with the advantages of forward modulation technology and light wavelength division multiplexing technology. It simplifies the complexity of the system, reduces the cost of the ROF system, reduces the error rate and improves the performance of the whole system.