Abstract: Previous studies on the multilayer clamping high pressure vessel primarily focused on exploring whether it could meet the strength and usage requirements as a static device. However, with the continuous development of production demands, the multilayer clamping high pressure vessel has gradually been employed in high-pressure fatigue conditions, making its design under fatigue conditions increasingly important. To address this, this study considered the frictional contact between non-welded areas of layers, employing finite element analysis methods, and conducted an in-depth study on the stress conditions of the weld area under fatigue loads according to various authoritative standards. Based on structural stress methods and fracture mechanics, the welding joint was subjected to fatigue assessment. The results indicated the presence of stress concentration in the weld area at the end section, significantly reducing the equipment's fatigue life, with a minimum life of 39648 cycles. Subsequently, this study proposed a new structure, which could reduce the stress levels in the welding-intensive area at the end section under internal pressure. In the new structure, the additional bending moment and part of the axial load in the discontinuous region of the end will have to be borne by the integral forging. This has significantly increased the equipment's fatigue life, with a minimum life of 4.10×10⁵ cycles.