In the stability analysis and design of rock support for tunnels, the establishment of a refined numerical model relies on reliable and accurate geometrical information of structural planes. To better analyze and optimize the tunnel construction method and support mode, it is crucial to establish a refined numerical model for the tunnel. Based on the developed geotechnical intelligent analysis and multi-interpretation system, the feature extraction and interpretation of the rock mass structural surface are achieved. Meanwhile, coupled with multiple geological information, the comprehensive analysis and judgment of rock mass structural surface information are achieved through continuous dynamic tracking. According to this method, based on grade IV fractured rock data collected from the construction site of Dapuling tunnel, the safe distance of step in bench excavation method has been optimized based on the numerical modelling, and the corresponding bolt support design. The optimized tunnel excavation process is more stable and safer, providing a scientific basis for predicting, identifying, controlling, and preventing rockfall disasters during the excavation process of tunnels and underground caverns in fractured rock masses.