The invention discloses a terahertz frequency tripler based on coplanar waveguide transmission wires. The terahertz frequency tripler based on the coplanar waveguide transmission wires comprises three waveguides, including a fundamental wave input wave guide, an output waveguide and a main body waveguide, a dielectric substrate inside the main body waveguide, and electrical structures arranged on the dielectric substrate through the coplanar waveguide transmission wires in an integrated mode, wherein the electrical structures are composed of a DC (direct current) bias low-pass filter, an input matching transmission wire, a fundamental wave low-pass filter, a fundamental wave matching transmission wire, a triple-harmonic matching transmission wire, a three-stage matching transmission wire, a four-stage matching transmission wire and an output matching transmission wire from left to right and takes the coplanar waveguide transmission wires as a ground wire. The coplanar waveguide transmission wires substitute traditional microstrip wires and traditional suspended microstrip wires for designing the peripheral passive circuit of the frequency tripler; the inside of the circuit is directly connected with a cavity wall to achieve a radio frequency grounding and DC circuit; by means of a fundamental wave input duplexer, DC bias and other circuits can be designed simultaneously, subsequent assembling steps can be reduced, and the circuit structure is easy to process and assemble.