In the whole research process of electromagnetic wave, the research ofterahertz wave belongs to a blank for a long time, which is the least knownand least developed by far. But now, people are trying to make up the blankand develop terahertz better and better. The charm of terahertz wave originates from its multiple attributes, including electromagnetic field attribute,photon attribute and thermal attribute, which also attracts the attention ofresearchers in different fields and different countries, and also terahertztechnology have been rated as one of the top ten technologies to change thefuture world by the United States. The multiple attributes of terahertz makeit have broad application prospects in military and civil fields, such as medical imaging, astronomical observation, 6G communication, environmentalmonitoring and material analysis. It is no exaggeration to say that masteringterahertz technology means mastering the future. However, it is because ofthe multiple attributes of terahertz that the terahertz wave is difficult to bemastered. Although terahertz has been applied in some fields, controllingterahertz (such as generation and detection) is still an important issue. Nowadays, a variety of terahertz generation and detection technologies havebeen developed and continuously improved. In this paper, the main terahertz generation and detection technologies (including already practical anddeveloping) are reviewed in terms of scientific and engineering principles,in order to provide a systematic and up-to-date reference for researchers interahertz field.