Although performing tunnel excavation using tunnel boring machines (TBMs) is rapid, it is susceptible to the unexpected geological changes located in front of the tunnel face. Seismic detection methods are useful to detect local geological conditions in front of the tunnel face. However, manual detection is time consuming and may interfere in realizing rapid excavation by TBMs. Therefore, this study proposes an automated seismic detection system that is mounted on a TBM for rapidly imaging anomalous zones in front of the tunnel face. The system consists of an automated data acquisition system and a data processing system. The automated data acquisition system allows reducing the data acquisition time. To reduce the data processing time, the data processing system images the anomalous zones based on a modified Coppens' method. The proposed system has been mounted on TBMs and verified based on field tests.