In order to overcome the influence of dispersion on optical millimeter-wave transmission with carrier suppression modulation,a modified carrier suppression modulation scheme is proposed.With two-input radio frequency signal phases,base-band signal gain and bias adjustment,a dual-drive Mach-Zehnder modulator(MZM) is used to generate carrier-suppression-modulation optical millimeter-wave with signal only carried by one first-order sideband.Theoretical analysis shows that the proposed scheme solves the problem of time shift of code caused by chromatic dispersion compared with traditional schemes,and the transmission distance is extended greatly.Simulation results show that the eye diagram keeps open and clear even when the optical millimeter-wave signals are transmitted over 110 km.The power penalty values are about 0.78 dB,1.7 dB and 1.9 dB at a BER of 10-10 after transmission of 20 km,40 km and 60 km,respectively.