The invention discloses a terahertz multi-carrier communication system. The system comprises a transmitter and a receiver. The transmitter comprises a transmitter terahertz antenna, a transmitter terahertz radio frequency front end, a transmitter intermediate frequency circuit and a transmitter baseband circuit. The receiver comprises a receiver terahertz antenna, a receiver terahertz radio frequency front end, a receiver intermediate frequency circuit and a receiver baseband circuit. The transmitter baseband circuit comprises N paths of DACs, and the receiver baseband circuit comprises N paths of ADCs, wherein N is a positive integer greater than or equal to 2. According to the invention, the front-end circuit part is improved, N paths of DAC signals are moved to different frequency bandsfor combining. According to the technical scheme of the invention, the Terahertz signal is combined and then the combined signal is moved to the Terahertz channel, namely, a multi-carrier mode is adopted, the spectrum resource of the Terahertz channel is utilized to the maximum extent, the communication rate is N times of that of a multi-carrier system under the condition of the same ADC samplingrate, and meanwhile, the use efficiency of the spectrum resource is greatly improved.