Terahertz (THz) waves have gained remarkable applications in the fields of detection and communication. THz wave non-destructive testing (THz-NDT) technology can penetrate the surface mask layer without damaging the material itself and achieve high-resolution recognition of material characteristics, which has a wide range of application prospects in material testing, especially in the field of coating detection. The research progress of THz-NDT technology in coating materials detection both internationally and domestically in recent years is reviewed, and the current status and trend of its development are summarized and outlooked to provide necessary reference basis and research ideas for its further application.