Abstract: In this study, a 5 000 m3 in-service propane spherical tank is selected as the research object, and the finite element models of circumferential offset and radial offset of the bottom of a single pillar are established respectively. Through the buckling response analysis carried out on the ANSYS Workbench platform, the limit values under the circumferential offset and the radial offset are obtained, and the buckling deformation law of the spherical tank under the pillar offset is studied. On this basis, the buckling analysis of the spherical tank is carried out according to the measured offset data of the pillar. It is found that there is no buckling in the radial outer offset of the bottom of the pillar within the studied offset range. The limit value of the radial inner offset of the bottom of the pillar is larger than that of the bottom circumferential offset, and the buckling deformation of the radial inner offset of the bottom of the pillar is smaller than that of the bottom circumferential offset. It shows that the bottom of the spherical tank pillar is easier to buckle when it is offset in the circumferential direction, and it is the most difficult to buckle when it is offset radially outside the bottom of the pillar. The position of the maximum buckling deformation of the spherical tank is at the tie rod, and the buckling response of the spherical tank under the radial inner offset and circumferential offset at the bottom of the pillar conforms to the characteristics of branch buckling.