Spherical bulkheads are widely used in large-deep submersibles due to their highvolume-weight ratio and material utilization. The sphere-toroid-cylinder combined spherical bulkhead hasthe advantages of a simple structural style, clear mechanical property and relatively low constructiondifficulty, resulting in great engineering applicability. In this paper, spherical bulkheads withsphere-toroid-cylinder combination are studied, and their stress strength characteristics under uniformexternal pressure are anal...