By using 3d geological modeling technology to establish the true 3D geological model of Wulongshan Tunnel, based on the core idea of the ADECO-RS, simulation calculation was carried out through FLAC3D program, the construction method of full section excavation in the tunnel was optimized. The results show that there is no need to pre-reinforce the tunnel face within the scope of action of the large pipe shed, outside the scope of the pipe shed, through the simulation and analysis of the different working conditions after the pre-reinforcement of the palm face, the results show that the glass fiber bars can effectively control the settlement of the top arch and reduce the extrusion displacement of the palm surface. After the glass fiber bars are used to strengthen the palm surface, the settlement of the top arch is reduced by about 40%, and the extrusion deformation of the palm surface is reduced by about 70%, the full section excavation of 1.8m per cycle can be realized after the palmtop is pre-strengthened outside the scope of the pipe shed. Based on the simulation of different working conditions, the curve inflection point of extrusion displacement of palm surface corresponding to different lap lengths is proposed to determine the minimum lap length of fiberglass bolt. The research results can provide reference for similar projects.