Abstract:Spectral fatigue analysis method for truss tubular joints is studied and used to analyze the truss tubular joints of a new-type production and storage SPAR based on the sea condition of South China Sea. The results show that the fatigue strength of truss tubular joints of the new-type SPAR satisfies design requirement， and the fatigue strength of columns is worse than that of braces. Contributions to fatigue damage by axial force，in-plane bending moment and out-of-plane bending moment of braces are analyzed individually as well. The results show that the fatigue damage at diagonal braces is mainly caused by axial force of braces，the fatigue damage at horizontal braces is mainly caused by in-plane bending moment，while out-of-plane bending moment has little effect on fatigue damage at all braces.