In frequency-modulation/continuous-wave (FM/CW) scannerless lidar system the intensity modulated (IM) laser transmitter of high-power is a key component for radar imaging. In order to realize target detection of long imaging range and high ranging accuracy,the transmitter needs to possess output optical power more than 10 W,optical modulation depth higher than 70%,better modulation linearity and radio frequency (RF) bandwidth broader than 200 MHz. This paper introduced various schemes of high-power laser modulation,including the direct modulation of diode lasers,the lithium niobate crystal bulk modulation and the combining waveguide modulated seed laser and optical amplification. Their advantages and disadvantages of schemes were analysed. Finally,the modulated lasers array based on multi-quantum well (MQW) electroabsorption modulation was put forward. As a transitional scheme,the optical modulation combining electroabsorption modulated laser and optical fiber amplification were shown in the paper.