[Objective] This study aims to reveal the patterns of wind-sand transport around railway bridges and the characteristics of sand accumulation on bridge surfaces under different horizontal curve radii in sandy regions, providing a theoretical basis for optimizing wind-sand protection designs for railway bridges in such areas. [Methods] Integrating field-measured wind dynamic environment data, computational fluid dynamics (CFD) methods were employed. Utilizing the Eulerian two-fluid model, simulations were conducted for a 9 m/s incoming wind velocity, with horizontal curve radii (R) of 200 m, 400 m, and 600 m. [Results] Numerical simulations revealed: (1) The flow field around the railway bridge exhibits distinct functional zones (deceleration zone, acceleration zone, vortex zone), with the extent of these zones influenced by the bridge's curvature. (2) The geometric configuration of the bridge's windward surface (convex or concave) induces "guiding" or "converging" effects on the wind-sand flow. (2) The geometric shape of the bridge's windward face (convex or concave) induces either a "guiding" or "converging" effect on the wind-sand flow, serving as a key factor influencing sediment deposition distribution on the railway bridge surface. (3)A larger horizontal curve radius of a railway bridge results in more uniform wind speed distribution across the deck, stronger overall sediment transport capacity, and reduced sediment accumulation on the bridge surface. [Conclusion] When designing railway bridges in sandy regions, prioritize larger horizontal curve radii. Align the bridge's "convex surface" toward the prevailing wind direction to effectively channel wind-sand flows and significantly mitigate sand accumulation hazards.