Terahertz (THz)wave has many unique properties and broad prospects in many fields of science and technology. However，due to the strong water vapor absorption of THz wave in air，the transmitting distances of THz wave are very limited，which restricts the THz applications. How to implement THz remote detection becomes the focus of the study in the THz field. This paper focuses on the recent remote THz wave detecting method of THz-REEF and TEA，analyzes the detecting process and the structure of the detecting system，explains the intrinsic physical mechanism，and look into the future of THz applications.