Abstract: In this paper, combined with the typical engineering examples, aiming at the phenomenon of shotcrete spalling of concrete and cracks, we study deformation mechanism and failure characteristics of the primary support system, and propose two kinds of primary support optimization schemes. Using numerical simulation, we compare the supporting effect of optimization schemes. The results show that the anchor is the main initial support of shaft, but, in the case of low strength and relatively broken rock mass, the supporting role of the bolt is weakened, the steel arch is needed to control the stability of the wall surrounding rock. The displacement of the well wall is reduced by 16% through the increase of the length and density of the bolt. Enhance steel arch type and increase the density of steel arch can reduce the displacement of shaft wall by 47%, the plastic yield range is reduced by more than 50%.