Abstract: Terahertz atmospheric transmission is an important part of science and technology, it is permeated almost all applications of terahertz technology. Research on terahertz atmospheric transmission is nearly horizontal level paths in the existing literature. This paper presents a dispersion attenuation model of terahertz atmospheric transmission based on the radiation transfer, dispersion theory and Van-Vleck Weisskopf line-shape combined with Jet Propulsion Laboratory (JPL) database. The absorbing attenuation characteristics of terahertz atmospheric transmission along the slant path between 0.1 and 1 THz are studied using this model. The window structure of terahertz atmospheric transmission is analyzed and provides a theoretical reference for terahertz ground-space communication.