Aiming at the difficulty of quality detection of cigarette filters implanted with capsules, a non-destructive quality detection technology based on terahertz spectral information was proposed. According to the parameters of offset and transmittance, a capsules detection model is established to realize real-time and high-speed detection of different quality problems such as leaking, cracked, and offset beads. The results show that the detection speed of the system can reach 1000 pieces/min, and the detection accuracy exceeds 94%.