Abstract: To further investigate the vibration response characteristics of steel catenary risers, this study employs the Van Der Pol wake oscillator model to analyze the vibration response characteristics of a marine steel catenary riser subjected to both logarithmic shear external flows and internal flows. The results indicate that the vibration of the riser exhibits a combination of standing and traveling waves. With increasing internal flow velocity, the response shifts from being dominated by standing waves to traveling waves. As the shear intensity of the external flow profile increases, the maximum root mean square displacement of the riser vibration gradually decreases. The variation in the maximum root mean square change displacement with internal flow velocity is related to the change in traveling wave propagation direction. The vibration response of the riser exhibits obvious multi-frequency characteristics, and as the external flow shear degree intensifies, the main vibration frequency of the riser continuously increases. However, under the same external flow profile, as the internal flow velocity increases, the dominant vibration frequency gradually decreases. The vibration involves multiple competing modes, and there is a competitive relationship between each mode, which exhibits spatial competition and temporal switching during the dynamic response. The research results provide valuable insights for the subsequent fatigue prediction of steel catenary risers.