Ridge tillage is a major farmland management practice in arid and semi-arid areas; however, knowledge regarding wind velocity fluctuations and sediment transport characteristics over the ridged surface remains limited. This study used wind tunnel experiments to reveal the mechanism by which changes in ridge size and configuration affect wind velocity fluctuation near the surface and further influence the sediment transport rate (q). Results showed that ridge covering, compared with no ridges, significantly reduced the intensity and variation amplitude of instantaneous wind velocity (ui) in the lower layer, and changed its structure with measurement height (h). Wind velocity fluctuation intensity (uv) over all the ridges increased with incoming friction velocity (u*r), but first increases and then decreases with h. At the surface (h=0.01 m), the average wind velocity fluctuation intensity (uv_ave) increased linearly with both ridge spacing (L) and u*r, whereas its relationship with ridge height (H) was not obvious. The spatial variation in uv led to an uneven wind erosion distribution on the bed surface. With different ridge sizes, location and extent of wind erosion and deposition areas were significantly different. Finally, a quantitative relationship between the uv_ave and q under ridge-shaped microtopography conditions was established.