Terahertz (THz) waves, due to their unique physical properties, have broad application prospects in the field of imaging. As an emerging imaging technique, terahertz imaging offers advantages such as non-invasive, non-destructive detection and high resolution. In recent years, it has achieved significant progress across various domains. This article reviews the primary technological approaches and current research status of terahertz imaging. Firstly, based on the type of signal source, the characteristics of pulsed terahertz imaging and continuous-wave terahertz imaging systems are discussed, along with the basics of raster scanning-based imaging. Key terahertz imaging modalities, including near-field imaging, time-of-flight imaging, and computed tomography imaging, are highlighted and analyzed in detail. Next, the paper focuses on two technological solutions with the potential for real-time imaging: terahertz array imaging and terahertz single-pixel imaging. Their advantages and current developments in high-speed real-time terahertz imaging scenarios are analyzed. Finally, the article concludes with a summary of the application prospects, challenges, and future trends of terahertz imaging technology.