In recent years, the telecom network fraud gang is basically located outside the country, which brings great difficulty to the public security organs. In the face of such crimes, the big data investigation of the public security organs shows the limitations of data acquisition and criminal proof. Therefore, the investigators need to find and prove the facts of the case through interrogation. However, the current interrogation work of the public security organs is faced with many difficulties, such as the structural defects of the knowledge age of interrogation talents, the contradiction of investigation fragmentation and the integration of interrogation work, the increasingly complicated crime mode of electric fraud cases, and the increasingly strengthened anti-interrogation ability of electric fraud elements. In view of this, the public security organs should improve the effectiveness of investigation and interrogation as soon as possible from several aspects of cultivating interrogation talents with multiple knowledge structure, strengthening the investigation cooperation of cross-border electric fraud cases, and formulating interrogation strategies and interrogation guidelines. At the same time, the public security organs should also pay attention to the prevention and control of the legal risks and evidence authenticity risks in the investigation and interrogation.