The invention discloses a system and method for transmitting a terahertz radar signal based on digital pre-distortion. The system comprises a radar signal generation module, a clock control module, a digital pre-distortion module, a digital up-conversion module, a digital-to-analog conversion module, a frequency mixing module, a terahertz frequency doubling power amplification module and a radar antenna. The method comprises the steps of receiving data, updating a weight coefficient, obtaining a non-linear compensation signal, obtaining a digital up-conversion signal, obtaining a radio-frequency signal, conducting frequency doubling amplification, and transmitting a terahertz signal. By the adoption of the digital pre-distortion module, non-linear compensation is carried out on a digital baseband signal at the front end of a terahertz radar, and the performance of the terahertz radar transmission system is improved. The digital pre-distortion method is achieved by the adoption of a high-speed field programmable gate array, and the effective bandwidth and the spectral efficiency of the signals are improved.