Terahertz science and technology is increasingly emphasized in science and industry, and has progressed significantly in recent years．There is an important aspect of attention in the application of terahertz technology to medicine．The overview of the terahertz characters, terahertz spectroscopy and terahertz imaging technology is introduced．This paper focuses on reviewing the use of and research progress in terahertz spectroscopy and terahertz imaging technology in medical testing and diagnosis．Furthermore, the problems to be solved and development directions of terahertz spectroscopy and terahertz imaging technology are discussed.