A symmetrical wedge-to-wedge THz hybrid SPPs waveguide (WWTHSW) with low propagation loss is investigated. The WWTHSW consists of two identical dielectric wedge waveguides symmetrically placed on each side of a micro wedge-patterned thin metal film. The mode characteristics of the WWTHSW, such as the propagation length ( L _p), the normalized effective mode area ( A) and the figure of merit (FOM) are analyzed by using the finite element method (FEM). Firstly, the influences of the height of Si micro wedge waveguide ( H)and the gap between two wedges ( g) on L _pand Aare studied. For the same g, Afirst decreases and then increases with the increase of H. Aachieves a minimum at an Hof ~40 μm. However, L _pmonotonically increases as Hincreases. The change of L _pslows down when His greater than 40 μm. At a fixed H, L _pslightly increases with the increase of g. But Aachieves a minimum when gis ~50 nm. Secondly, the dependencies of the mode characteristics of the WWTHSW on Si wedge tip angle ( α) and Ag wedge tip angle ( θ) are analyzed. At a fixed α, θhas less effect on L _pand A. As αincreases at a fixed θ, L _pincreases monotonically but Adecreases firstly and then increases. Areaches a minimum when αincreases to ~100°. Then, the change of L _pand Awith the thicknesses of Ag film ( d) and Ag wedge ( h) are demonstrated. At a fixed h, both L _pand Aslightly decrease as dincreases. For the same d, L _pand Adecrease with the increase of h. Afor h= 0 μm is distinctly larger than those for h= 2 μm and h= 5 μm. According to the above optimizations, the parameters of the WWTHSW are chosen as d= 100 nm, g= 50 nm, h= 2 μm, θ= 80°, α= 100°, H= 40 μm. Under the optimal parameters, L _pof ~51 mm is obtained when A _mreaches ~ λ ²/10280. Compared with the previous hybrid THz plasmonic waveguide, L _pof the WWTHSW increases by 3 times, and Adecreases by an order of magnitude. This result reveals that the WWTHSW enables low-loss propagation and ultra-deep-subwavelength mode confinement at THz frequencies. At last, the coupling property of the parallel WWTHSW is investigated. The coupling length of ~8958 μm is achieved without the crosstalk between two parallel waveguides. By comparison, the WWTHSW has more advantages in terms of transmission and coupling characteristics than the previous micro wedge waveguide structure and bow-tie waveguide structure. In summary, due to the excellent transmission and coupling characteristics, the WWTHSW has great potential in the fields of optical force in trapping, biomolecules transporting, and in high-density integrated circuits design.