Photonic crystal fiber-based heptagonal cladding with the elliptical rotated-Hexa core is reported in the terahertz waveguide for the applications of communication area in this paper. By utilizing the photonic crystal fiber concept, all numerical results have been obtained by the finite element method with perfectly matched layers based on the COMSOL Multiphysics computer software tool. This H-PCF fiber shows a low effective material loss of 0.0076 cm⁻¹, with a larger effective area of 5.95 × 10^–8 m², power flows within the core area of 90%, confinement loss of 3.35 × 10^–16 cm⁻¹, and scattering loss of 1.24 × 10^–10 cm⁻¹ at 1 THz. Besides, other optical properties like confinement loss, scattering loss, power fraction, V-parameter, and effective area have also been considered briefly. So, it is expected that the mentioned H-PCF structure-based waveguide will significantly improve many kinds of communication fields of the THz technology.