Terahertz (THz) waves are located between the infrared and microwave bands. Compared with other bands, they have the characteristics of high transmission, low energy, coherence and transient nature. With the widespread application of terahertz imaging technology in the fields of space communication, radar detection, aerospace and biomedicine, it has been shown that THz imaging offers advantages over traditional imaging technologies (such as ultrasonic imaging and X-ray imaging). This paper first introduces the development status of THz time-domain spectroscopy (THz-TDS) imaging technology and room temperature (uncooled) microbolometer THz imaging technology. Subsequently, typical applications of THz imaging technology are presented. Finally, the limiting factors of THz imaging technology are discussed.