We numerically investigate a waveguide of metal pillar arrays (MPAs) and a hybrid waveguide consisting of the MPAs and a dielectric film in 0.1-1.0 THz. The numerical results show two resonance modes with a bandgap of 0.14 THz are supported in MPAs. The propagation loss and field confinement can be modified by the addition of a low loss dielectric film by tuning the film thickness and the refractive index. The investigation shows that the lowest loss of the hybrid structures is less than 0.1 cm-1 at 0.68 THz and the THz waves are tightly confined inside the hybrid waveguide. This work shows the hybrid waveguides are promising towards compact integrated terahertz devices in communication and sensing.