The invention relates to a passenger luggage security inspection system, in particular to a terahertz imaging passenger luggage rapid security inspection system and a dangerous goods detection method of the terahertz imaging passenger luggage rapid security inspection system. Terahertz rays are focused on passenger luggage by controlling a two-dimensional transversely-moving platform through a computer, and are received by a detector after being reflected by passenger luggage and focused by a lens, terahertz signals are converted into voltage signals, and images are output through the computer after noise reduction and amplification are conducted on the voltage signals. The problems that during X-ray detection, hurts are great, formed images are not clear, luggage simultaneous detection signals interfere with one another, and a detection device is complex in structure, large in occupied area, low in detection efficiency and high in cost are solved. The terahertz imaging passenger luggage rapid security inspection system and the dangerous goods detection method are wide in application range, accurate in detection, small and exquisite in structure, and capable of simultaneously conducting security inspection on passenger luggage, and the potential safety hazards of public places are reduced on the premise of efficient security inspection.