In order to reduce the construction risk of the portal section of shallow buried tunnel with bias pressure，the deformation of surrounding rock was effectively controlled. Taking the construction of the entrance section of the tunnel of expressway in Yushi county，Guizhou province as an example， the three-dimensional numerical simulation model was established to analyse the combined support scheme of advanced pipe shed and biased retaining wall. Compared with the monitoring results，the supporting effect of the combined support scheme was discussed. The results show that the deformation of surrounding rock at the portal section of shallow bias tunnel can be controlled satisfactorily using the combined support. The sink of tunnel at vault，the convergence of wall，the subsidence of surface can be effectively limited. The accuracy of the numerical simulation results is also verified by the monitoring data. Therefore，the combined support scheme of advanced pipe shed and bias retaining wall can be considered as a reliable and effective support in the construction process of the entrance of shallow buried tunnel with bias pressure. The research can provide reference for similar projects.