Terahertz (THz) technology, an emerging non-destructive detection method, holds significant potential for firearm inspection. Operating in the 0.1–10 THz range between microwaves and infrared radiation, THz waves penetrate non-polar materials (e.g., clothing, plastics, ceramics) while avoiding radiation risks due to their non-ionizing nature—unlike conventional X-rays. This technology primarily employs imaging for firearm identification: Passive THz imaging (PTI) visualizes concealed weapons (e.g., ceramic pistols, plastic knives) through packaging materials by detecting reflectivity contrasts, achieving millimeter-scale resolutions (<5 mm) for non-metallic threats. Currently deployed in security applications across the United States, Europe, and China—including L-3 Communications’ passive imagers (full-body scans in 3 s at airports) and China’s active systems (rapid firearm screening at high-speed rail and customs checkpoints)—THz technology still faces critical bottlenecks:(1) Insufficient source power from emitters for long-range detection;(2) Imaging degradation in humid environments due to strong water vapor absorption;(3) Real-time processing limitations caused by point-by-point scanning in pulsed THz systems, hindering high-throughput security screening efficiency.