Abstract: The calculated results by using the finite element software, Plaxis, are adopted to simulate the excavation of Samsung Digital Building in Qingdao, which are coincident well with the test data. Through the analysis of the deformation of excavation and the distribution of internal force on supporting structure，it is proved that the deformation above the rock is more obvious, and the prestressed anchor bar is effective in changing the stress distribution in the soil and protecting the foundation from evident displacement. It is effective to use pile anchor in soil-rock dualistic structure. It is helpful to use the Plaxis for the design and construction of excavations.