The invention discloses a terahertz band-rejection filter comprising N×N identical units, which are periodically arranged on a plane perpendicular to the incident direction of the terahertz wave, and there is no space between adjacent units, N is an integer greater than or equal to 2, and a single The unit includes a first metal resonant layer, a second metal resonant layer, and a substrate; the first metal resonant layer is attached to the center of the upper surface of the substrate, and the second metal resonant layer is attached to the center of the lower surface of the substrate; the first metal resonator Both the first metal resonant layer and the second metal resonant layer are cross-shaped and have the same size; after the wave is incident, electromagnetic resonance is generated on the first metal resonant layer and the second metal resonant layer, and the electromagnetic energy at the resonant frequency is used to maintain electronic oscillation, thus Form the filter stopband. The invention has the advantages of rapid attenuation of the stop band, fine-tuning and wide-range adjustment of the bandwidth, simple structure and easy manufacture, low cost, etc., and simplifies the structure of the terahertz band-stop filter.