Wound wire bundles are often used in reactor structural components. The winding wire can not only prevent the vibration of the pipes, but also strengthen the heat exchange between the pipes. Because of its advantages in heat transfer, the wound wire bundle structure has been used in both core and OTSG.In this paper, the u-shaped 4-wound wire bundle structure is regarded as the research object, and four commonly turbulence models are used for calculation based on CFD program. Radial flow characteristics under different turbulence models are obtained through the given velocity inlet. What’s more, it is found that the SST k-ω model are shown better performance, when applied in the 4-wound wire bundle structure with the consideration of computer performance and calculation accuracy. The radial velocity of the three axial paths and the flow pressure at the center of the B-B slit show periodic distribution with a period of one quarter pitch. Due to the interaction between wire winding, there appears obvious flow pulsation in the radial direction of the central sub-channel in the structure of 4-wound wire bundle.