With its unique technical advantages, such as transient, broadband, coherence, low energy, penetration and absorption, terahertz(THz) radiation has been highly regarded by governments, universities and research institutions worldwide and is becoming an emerging research hotspot in the fields of biomedicine, materials science and physics. Crop components such as water, protein, fat and starch are theoretically more abundantly absorbed in the THz spectra region; The low radiation properties of THz are safer for the detection of agricultural biological samples. The penetration characteristics of THz spectroscopy are unique for the detection of packaged and coated samples. Terahertz time-domain spectroscopy(THz-TDS) combined with imaging technology is used further to evaluate the histomorphology of crop samples for discrimination. Therefore, THz technology is becoming a promising cutting-edge analytical technology in crop quality inspection. In this review, the basic principles of THz-TDS and imaging technology are briefly described. The current research status of THz-TDS and imaging technology in the field of crop quality inspection is focused on the recent research progress and problems of the technology in the field of crop seed quality identification (e.g. variety, transgenic and vigor), crop composition analysis (e.g., sugars, moisture and starch), crop storage quality discrimination (e.g., freshness, deterioration and insect damage) and agricultural product safety detection (e.g., pesticide residues, illegal additives and foreign substances) are summarized, and the application prospects and development trends of THz technology in the field of crop quality inspection have prospected.