Abstract: The experimental study on the reinforcement of desert aeolian sand by microbially induced carbonate precipitation (MICP) technology was carried out at the unit scale and the model scale. At the unit scale, explored were the effects of different grouting batches and different concentrations of the cementation solution on the physical and mechanical properties of the reinforced samples, and analyzed was the microscopic mechanism of MICP reinforcement of desert aeolian sand by SEM and XRD tests. Based on the unit scale test results, model scale test was carried out to evaluate the feasibility of MICP method on the reinforcement of desert aeolian sand. The unit scale test results showed that: after five grouting batches, the average content of calcium carbonate in sand column reached 22.28%~29.09%, the dry density reached 2.21 g/cm³~2.46 g/cm³, and the maximum shear P-wave velocity was about 574 m/s; as the concentration increased, the physical and mechanical properties initially increased and then decreased; the optimal concentration of the cementation solution was 0.75 mol/L, and the highest unconfined compression strength could reach 30.02 MPa. The calcium carbonate crystal formed by MICP treatment was basically composed of calcite, which was mainly distributed on the surface of sand particles and at particle contacts. The results of the model scale test showed that: the loose sand column could be reinforced as a whole; the upper part of the column had the best reinforcement effect, followed by the middle part, and the lower part was the worst. The reason for the inhomogeneity might be that the tube was blocked to a certain degree at the later stage of MICP process, resulting in a small range of effective grouting radius in the middle and lower parts of the model sample, thus affecting the reinforcement effect of the middle and lower parts. This research can provide a data support and a theoretical basis for the reinforcement of desert aeolian sand by MICP technology.