Terahertz(THz) waves, situated between the infrared and microwave bands, possess unique properties such as high transmissivity, low photon energy, coherence, fingerprint spectra, and transient characteristics. Compared with microwaves, X-rays, and other technologies, they have greater advantages in imaging and can compensate for the shortcomings of traditional imaging technologies. With advancements in photonic and microelectronic technologies, terahertz imaging has been widely applied and has achieved significant results in fields such as non-destructive testing, biochemical sensing, and material analysis. This paper systematically reviews the research progress in terahertz(THz) imaging technologies, focusing on raster-scanning imaging, Focal-Plane Array(FPA) imaging, Synthetic Aperture Radar(SAR) imaging, and near-field imaging techniques, while analyzing the resolution, speed, and suitable application scenarios of each technology. It also highlights the critical role of terahertz imaging in materials science, cultural heritage inspection, and biomedical applications, discusses its current limitations, and outlines future development directions.