According to the principle of TGP tunnel geological prediction system and the problem existent in the process of detection, this paper has discussed some abnormal-signal-induced factors such as external pulse signal interference, current interference, poor coupling, pipe wave and charging parameters in the data collection, and analyzed the cause of resultant errors with the feedback from engineering application. On such a basis, some suggestions were put forward on improving the understanding of anomalous seismic wave and geological work as well as edge diffraction wave for avoiding the abnormal signal generation and reception. It is concluded that the collection of reliable data is an essential and efficient way to improve the accuracy of TGP system data interpretation.