Hierarchical semiconducting metal oxide is highly active due to its special stereostructure, which is potential adsorbent for dye contaminants. Precursors of MoO₂ hollow spheres were successfully synthesized via a simple and one-step solvothermal method. And hierarchical α-MoO₃ hollow microspheres were obtained after subsequent calcination at 400 ℃. Diameters of the α-MoO₃ microspheres were about 600-800 nm which were assembled by nanorods with a width of 70 nm. The as-obtained α-MoO₃ nanomaterials presented excellent adsorption performance for methylene blue (MB). MB removal percentage attained 73.40% in the first 5 min when the concentration of α-MoO₃ absorbent was 0.5 g/L in MB solution at the concentration of 20 mg/L. The equilibrium was established after adsorption for 60 min, and the removal percentages stabilized in the range of 97.53%-99.65%. Their adsorption kinetics was well fitted to a pseudo-second-order model. The adsorption isotherm conformed to Langmuir isotherm model, and the maximum uptake capacity was 1543.2 mg/g. The α-MoO₃ microspheres are cost-effective, fast and complete for MB removal owing to its hierarchical and hollow nanostructures, which also can be employed for adsorption of other organic dyes in waste water.