Abstract: In large-scale deep excavation, earth berm support has been widely used due to economy and convenient construction, but the existing standards do not give a design method. The V-area excavation of Beijing Sub-Central Station, the largest underground comprehensive transportation hub in Asia, is supported by two-stage earth berm, with an excavation depth of 34.4 m and strict deformation requirements. The support effect was studied through three-dimensional numerical simulation, a finite element model containing 19 calculation stages was established, and the HSs model parameters suitable for the soil layer in Beijing were determined based on relevant test results. The finite element prediction results show that the support system can meet the engineering requirements, and the supporting effect of the earth berm is significant. At the same time, the calculation results of the small strain model and the commonly used Mohr-Coulomb model was compared, the results of which show even if the stiffness of the Mohr-Coulomb model is artificially increased, reasonable deformation prediction cannot be obtained due to its single modulus parameter, as a result, the small strain stiffness of soil must be considered in the deformation calculation of deep excavation, but the Mohr-Coulomb model is close to the small strain model in the calculation of the internal force of the supporting structure.