Terahertz technology is widely used in the field of nondestructive testing owing to its unique characteristics such as excellent perspective, low energy, high spectral resolution, and exceptional time resolution. The terahertz technology is particularly useful in obtaining the spectral information of precious cultural relics and can confirm the defect positions in their internal structure. These results can provide the technical support for subsequent conservation of cultural relics. This paper summarizes the domestic and international application prospects of terahertz spectroscopy and imaging technology in nondestructive and in situ testing. Terahertz technology can satisfy the requirements of national conversation, which is contributed to solve the exact problem of domestic cultural relic restoration. It has a certain promotion value and is of considerable significance for national conversation.