In order to ensure the construction safety of tunnels in water-rich sections near reservoir areas, it is very important to adopt comprehensive and reliable advanced geological prediction technology combined with on-site monitoring and measurement. Taking the Chenlingding tunnel as an example, through the comprehensive geological prediction of the broken rock section near the reservoir, the numerical model of the broken rock section was established, and compared with the field measurement data. The results show that the comprehensive advanced geological prediction system combining short, medium and long distances, such as geological radar, seismic wave reflection method and advanced horizontal drilling, has high accuracy in adverse geology, rock fragmentation and water rich conditions in the tunnel; The rich water condition, fault information and rock engineering geology provided by the advanced geological prediction can provide reliable guarantee for the tunnel excavation scheme, the preparation of advanced support measures and the formulation of emergency plans; The deformation trend of the deformation curve of the monitoring value and the simulation value is consistent. The initial ground settlement and vault settlement of the tunnel are relatively fast, and they are basically stable after 50 days, but both are less than the deformation amount reserved in the design scheme, indicating that the construction scheme is safe and reasonable, and the control effect is good, which can provide reference for the selection of advanced geological prediction methods and the formulation of construction scheme of water-rich tunnel.