Abstract: For large-section underground water sealed oil storage, the section form of the cavern is vital to the stability, durability and sealing performance of the stored oil, but the stability at the intersection of each tunnel and oil storage cavern is still a weak link when judging from the stability of the entire storage. One underground water sealed oil storage project in Liaoning was taken as the example, and the FLAC3D numerical analysis was performed on the stability at the intersection of the water sealed oil storage from the aspect of surrounding rock stress and displacement. The intersections, between the oil storage cavern and the construction tunnel, the connecting tunnel and the vertical shaft, were analyzed by software, in which the mechanical behavior of these intersections was analyzed, and the stress distribution, deformation characteristics and structural spatial stress characteristics around the cavern were verified. It is concluded that the stress concentration at the intersection does not exceed the compressive strength of the rock, and the magnitude and area of tensile stress also meet the requirements. Finally, the weak points in the simulation were pointed out, and suggestions were put forward to increase the reinforced support in design and to strengthen monitoring and measurement in construction.