In this study, tunnel karst characteristics, groundwater hydrochemical characteristics, and water inflow and water inflow disaster risk are evaluated in combination with the geological conditions of the tunnel area, and the tunnel karst control factors and disaster-causing modes are then analyzed. The analysis results reveal that the bedrock in the tunnel area is mainly limestone and marl, with a high CaCO3 content, resulting in surface dissolution landforms and strong karst characteristics of the hole body. The hydrochemical characteristics of groundwater are HCO3-CaMg, the water inflow can reach 8058.13 m3/d, and the danger degree of sudden water gushing is located in the medium-danger area ~ extremely high-danger area. The analysis of the disaster mode of tunnel water gushing includes three main categories: the asymptotic damage mode, infiltration instability failure mode and comprehensive damage mode, and the distribution lengths of the three modes are 1091.5 m, 2242.6 m and 689.7 m, respectively. This study provides ideas for the analysis of the water-gushing disaster mode of karst tunnels and provides some theoretical support for the prevention and control of water-gushing disasters.