Two expanding excavation schemes, Bench Expanding excavation Method (BEM) and Double-Straight Wall with 6-parts expanding excavation Method (DSW-6 M), were designed for the expanding excavation project in Loushan Tunnel in the soft surrounding rock section. The 3D finite-difference model was used to analyze the surrounding rock deformation and Ground Surface Settlement (GSS) caused by adopting different excavation schemes. The influence of non-uniform GSS on inclination of the High-Voltage Tower and the surrounding rock stat during expanding excavation were compared and analyzed by adopting different schemes. The results shown that DSW-6 M based on settlement control was better than BEM, and the reasons were analyzed by surrounding rock stat during construction. DSW-6 M was adopted in actual construction. The settlement prediction was in good agreement with the measured results. The rules between increasing rate of vault settlement and surface slope was obtained by analyzing the field monitoring data.