As the most widely used connection structure in deep-sea engineering, SCRs have a crucial impact on the development of oil and gas resources and engineering safety. To study the fatigue performance of SCRs under complex environmental loads, considering the excitation effect of platform motion on vortex-induced vibration, an OrcaFlex external interface was developed based on a two degree of freedom wake oscillator model. The dynamic motion calculation results of SCRs under complex environmental loads were solved, and the fatigue analysis of SCRs was carried out using the S-N curve method, Compare the fatigue characteristics of SCRs obtained by this method with those recommended by DNV specifications, and explore and summarize the influence of platform motion on the fatigue characteristics of SCRs.