As a typical thin-walled structure, large steel silos are widely used in industry and agriculture to store a large number of granular solid materials. In order to clarify the influence of steel silos on their stability under the action of discharge, the finite element software ABAQUS is used to carry out numerical simulations based on the European steel silo design code, and the first-order eigenvalue buckling mode of the improved steel silo is taken as the initial geometric defect, and its deformation characteristics, buckling modes and radial displacement under the action of unloading are studied. The results show that the steel silo is affected by complex side pressure and friction during the unloading process, which will cause the instability and failure of the silo wall, and the existence of initial geometric defects further reduces the buckling resistance of the steel silo. The results can provide some practical engineering value for the development of steel silo storage materials.