In order to analyze the influence of vortex-induced vibration on the strength and stability of marine drilling risers,a simplified analytical model was established and a method for calculating vortex-induced dynamic response was developed.A case study indicated that at primary resonance,first-order dynamic displacement response is greater than higher-order mode responses,but the influence of dynamic moment and shearing force of higher-order modes cannot be ignored.The natural frequency of risers decreased sharply with increasing length of the riser,but increased with increasing top tension.Various factors should be considered to avoid vortex-induced vibration in practical application,and the influence of vortex-induced vibration could be estimated by calculating the fatigue lifetime of riser.