In order to further reduce radio-over-fiber system cost and improve transmission performance, a novel optical carrier reuse mothed based on amplitude modulation in both uplink and downlink is proposed. The principle of the method is introduced, and its feasibility is verified by Optisystem software. The simulation results show that the performance of the system is optimal when the "0" code amplitude of the downlink transmission data is 1.4 V, the beam splittr's spectral ratio is 5∶5, and the modulator's extinction ratio is 5.2 dB.