The present disclosure describes a terahertz carrier sending apparatus and a terahertz carrier receiving apparatus. The sending apparatus includes a radio frequency sending chip, a mode conversion structure, a terahertz transmission line, and a circuit board. The radio frequency sending chip is packaged on the circuit board, and includes a radio frequency sending circuit, a feed transmission line, and a mode excitation structure. The mode conversion structure includes a metal inner wall, configured to couple a terahertz signal excited by the mode excitation structure into the terahertz transmission line. The terahertz transmission line is configured to transmit the terahertz signal. The receiving apparatus includes a similar part in a receiving direction. The subject matter herein implements efficient electromagnetic coupling and improves data transmission bandwidth.