Abstract: In order to obtain physical and mechanical characteristics of aeolian sand reinforced with alkali solution, laboratory tests were conducted to explore the changes in physical and mechanical parameters of aeolian sand after being treated with single alkali solution reinforcement and composite alkali solution reinforcement for durations of3,7,14,30,and60days at alkali solution concentrations of7%,14%,and21%.The mechanism of how alkali solution reinforces aeolian sand was briefly analyzed.The experimental results show that:(1) The addition of an alkali solution can improve the mechanical properties and water stability of aeolian sand.The shear strength parameters gradually increase with the duration of maintenance.The best reinforcement effect is achieved when the alkali solution concentration is14%.After60days of maintenance, the cohesive force and internal friction angle of the single alkali solution reinforcement samples and the composite alkali solution reinforcement samples have increased by48kPa and10°,and66kPa and9°,respectively, compared to plain soil.(2) The strength of the composite alkali solution reinforcement samples is slightly higher than that of the single alkali solution reinforcement samples, but the essence of the reinforcement is still the alkali-soil interaction.(3) The mechanism of alkali solution reinforcement of aeolian sand can be roughly divided into three phases: the filling phase, the cementation phase, and the dissolution phase.The research findings provide a new method for the reinforcement of aeolian sand and also offer fundamental data and scientific guidance for engineering construction in aeolian areas.