For the three-bucket jacket foundation, three different types of transition section structures are proposed. They are brace, inclined box, and flat box, respectively. The three-dimensional finite element software ABAQUS was used to study the natural vibration characteristics and the ultimate bearing capacity of the structure. The results show that the stiffness of the brace is smaller than the allowable natural frequency range. Compared to inclined boxtransition sections, the use of flat box has hzs increased the vertical, horizontal, and bending bearing capacity of the structure by 54.8%, 40.9%, and 48.6%, respectively. The research results can provide guidance for the selection of transition sections for the offshore three-bucket jacket foundation with large capacity.