Wind erosion mechanism is studied through interior wind erosion wind tunnel experiment for desert highway. The anti-wind erosion ability of Aeolian soil subgrade slope is equivalent to the variation of microstructure characteristics and shearing strength of Aeolian soil. Microstructure characteristics will be quantified analysis through scanning electron microscope and image analysis software for subgrade slope, and microstructure parameters are picked-up for wind erosion fore-and-aft. Aeolian soil’s Shearing strength and wind erosion depth are investigated at different position of windward slope during a long-time wind-blown. Then, wind erosion mechanism of Aeolian soils subgrade slope is clarified from two aspects of micro and macro, wind erosion influence depth is determined for certain environmental condition. Taking desert highway subgrade as an example, the results indicate that: the disturbance to the flow field enhances with the increase of slope ratio and subgrade height, wind erosion of the windward slope is severe. The anti-wind erosion ability on windward slope is weak obvious with the decreasing of soil’s water containing, the increasing of wind velocity and the blow time prolong. Shearing strength of Aeorian soil is gradually decreased from slope surface to its interior, from bottom to top of windward slope. According to environmental condition local, when average wind velocity is 11m/s and natural water containing is 2%, wind erosion depth is about 15mm on the top of slope which is 1/11 of subgrade height, relative to 10mm on the mid of slope. The conclusions drawn from micro and macro are proved the wind erosion mechanism of Aeolian soils subgrade slope perfectly.