Terahertz time-domain spectroscopy (THz-TDS) uses coherent detection method for spectrum analysis. The THz-TDS system integrates terahertz emitter and detector, which can simultaneously acquire the field intensity and phase information of terahertz pulses and be widely used in biology, materials, security, and other fields. The THz pulse induced by the ultrafast laser filament is an important way to generate wide-spectrum and high-intensity THz radiation. In this paper, the physical mechanisms of ultrafast laser filament radiated THz waves and the methods of enhancing and regulating THz waves are introduced in detail. The detection principle and methods of the THz-TDS system based on laser filamentation are described.