 Because of its high frequency and short wavelength, terahertz wave has a high signal to noise ratio in the time domain spectrum.Tomography using terahertz radiation can image samples that are opaque in the visible and near-infrared regions of the spectrum.Terahertz wave three-dimensional (3D) imaging technology has developed rapidly since its first successful application in 1997, and a series of new 3D imaging technologies have been proposed successively.