A symmetry thin-film waveguide stacked by photonic crystals multilayer films was investigated, and its first stop band of photonic crystal multilayer film lies in the range of 73～99 THz. For the electric-magnetic wave with the frequency range of 73～99 THz, its transmission properties in the waveguide were investigated based on multilayer dielectric waveguide analysis method. The results show that only TE0 and TM0 modes can propagate in guided layer, furthermore, its power constrained factor in the guided layer (central layer) is in 0.99～1, in other words, the electromagnetic wave at 73～99 THz is fully constrained in guided layer, for comparison, the power constrained factor of electric-magnetic wave with the frequency of 40 THz and 50 THz out of stop band is 0.84 and 0.86, respectively. Thus, based on the stop band properties of photonic crystal, the symmetry thin-film waveguide stacked by photonic crystals multilayer films exhibits ultra-low attenuation property.