Abstract: The technology method of active faults seismic risk assessment in Hohhot city and the activity characteristic of the major faults in the target area are analyzed to find out the maximum magnitude of potential earthquake in the major active faults. Through technology method of seismic hazard assessment of active fault, and the comprehensive analysis of the main fracture characteristics of target zone, we determine the future possible maximum magnitude of fracture in the target area. Using "time dependent" mainland model, BPT model and Hetao model, the seismic risk of target zone fracture was assessed comprehensively. The results show that the Hohhot segment and the Biqeq segment have a high degree of seismic risk in the coming 100 annual average. Among them, the seismic risk of the Hohhot segment is higher than the Biqeq section, the maximum magnitude of potential earthquake is M_S7.2.