Abstract: With the rapid development of China's economy and society in recent years, the demand for oil and natural gas is growing day by day, and a large number of underground energy reserves have begun to be built in salt rocks. Under the engineering background of a proposed underground oil storage group in bedded salt rocks in a salt mine in Jiangsu Province, a numerical simulation model of horizontal oil storage group was established with the finite element analysis method, using FLAC3D software as the platform. Meanwhile, the stability of storage group with different pillar widths in rectangular and diamond-shaped well layout was simulated and analyzed. In addition, the variation laws of the displacement distribution of surrounding rock, the volume shrinkage, the volume of plastic zone and the maximum vertical displacements of roof and floor after 30 years of operation of the storage groups were analyzed. The result shows that it is a reasonable layout to ensure the stability of the horizontal oil storage groups by adopting diamond-shaped well layout and setting the pillar widths not less than 1.75 times of the storage diameter. In addition, the results were verified according to the stability criterion, which shows that the stability conditions are satisfied. Generally, the research results could provide reference to the construction of underground oil storage groups in bedded salt rocks in China in the future.