Abstract: In recent years, the drum-shaped joints have become one of the commonly used joint forms in single-layer reticulated shells due to their simple construction, uniform force distribution, and convenient connection. However, the lack of corresponding design calculation methods and structural requirements in current codes severely restricts its engineering application. To address the application challenges of drum-shaped joints in practical engineering, this paper systematically studies the load-bearing capacity and failure mechanism of drum-shaped joints based on a large-span single-layer reticulated shell of a complex public building. Based on the Midas FEA NX finite element analysis platform, the study focuses on the influence of nodal wall thickness on the ultimate bearing capacity and failure modes of two types of drum-shaped joints—"without internal stiffeners" and "with internal stiffeners"—under axial force. The analysis results show that: For unstiffened drum-shaped joints, both bearing capacity and stiffness increase with the wall thickness. When the joint wall thickness is 2 to 2.5 times the member wall thickness, the joint’s bearing capacity exceeds that of the member. Internal stiffeners can effectively enhance the bearing capacity of drum-shaped joints to a certain extent. Under the premise of ensuring that the joint’s bearing capacity is higher than that of the member, drum-shaped joints without internal stiffeners are generally more cost-effective than those with stiffeners. The findings of this analysis can serve as a reference for the wall thickness design and stiffener configuration of drum-shaped joints, offering significant practical guidance.