This paper designs a new type of plastic terahertz photonic crystal waveguide

using polyethylene（PE） that contains periodically lined triangular lattice air holes for its cladding and ne polytetrafluoroethene（PTFE） for its core.Its dispersion characteristics curves are simulated by the FDTD method.The study results show that this plastic waveguide is a photonic bandgap effect waveguide appropriate for terahertz wave transmission and has good transmission characteristics in terahertz waveband.