In order to speed up the recovery of municipal road traffic, to effectively control the variable cross-section excavation steps and excavation angles, a method of reverse excavation in shallow buried tunnels with CRD variable cross-section has thus been proposed. A numerical model of FLAC3D variable cross-section excavation is established, and a comparison has been made between the effects of excavation brought about with different angles and excavation steps on the settlement and horizontal convergence of the vaults, followed by a comparative analysis of the field monitoring results and numerical simulation results. The experimental results show that it is easier to control the settlement and horizontal convergence with 30 degrees the excavation angle where, combined with the engineering construction factors, the recommended excavation distance will be 0.5 m. Both the settlement value and the horizontal convergence value have experienced a growth-stationary phase, with the results of field monitoring and numerical simulation basically identical in relevant data.