Abstract: To study the vortex-induced vibration (VIV) caused by current flow for the multi-lane wide section sub? merged floating tunnel (SFT) under water environment, which is suitable for traffic and safety needs, two numerical models for the wide cross-section with one-degree-of-freedom (1-DOF) and two-degree-of-freedom (2-DOF)were respectively established by using the Computational Fluid Dynamics (CFD) software Fluent. The distribution patterns of transverse displacement amplitude, lift coefficient amplitude, and mean drag coefficient versus the reduced current velocity for three types of wide sections (i.e., elliptical, round-end, octagonal section) are explored. By taking the round-end section as example, the time history curves and wake vortex shedding modes of the VIV under different reduced velocities, as well as the relations between the mass ratio, damping ratio and VIV characteristics of this type of wide section, were analyzed. The results show that the variation patterns of the transverse displacement amplitude, lift coefficient amplitude, and mean drag coefficient of these three types of wide sections are similar, and the VIV effects of the round-end section is the most significant. The transverse displacement and lift/drag coefficients within the locking range reach their extreme values and the wake vortex is in the“2P”mode, while those out? side the locking range are very small and the wake vortex is in the“2S”mode. The VIV effects are remarkable if the mass ratio and damping ratio are small, and a "beat" phenomenon was observed when the mass ratio was within a specific range. The numerical results based on the 2-DOF model are slightly larger than those based on the 1-DOF model, and the wake vortex shedding exhibits complex and variable patterns such as superimposed "8" shape and elliptical trajectories.