Abstract: This paper examines the cracks appeared in the retaining wall beside the FeiYuze tunnel uplink secondary lining vault. The seismic CT technology was used to investigate the engineering geology structure of the covering rock mass above the tunnel. The results indicate that the rock mass had three fracture zones along tunnel axial and the rock mass quality in the small mileage entrance section was poor. The rock section was treated accordingly. The fiber Bragg grating (FBG) sensor method was further used to monitor the tunnel structure. The results indicate that the loose and fractured rock mass were upgrated well by the applied reinforcements. Therefore, the seismic CT and FBG methods can confirm their examination results.