To study the optimal excavation method for shallow-buried soft rock large-section tunnels, detailed numerical models were established for the step method, the cross-middle wall method and the double side wall guiding pit method. The research focused on the time-space evolution of the ground displacement field during the construction process and the stress distribution of the supporting structure. The results show than the excavation using the double side wall guiding pit method induces smaller crown settlement displacements. The ground settlement caused by the three excavation methods is characterized by a U-shaped curve, with the double side wall guiding pit method resulting in the smallest surface settlement displacement. The initial support stress calculated for the double side wall guiding pit method is higher, but remains within a safe range.