Alumina supports have long played an essential role in the field of catalysis, but the traditional alumina must be improved due to its limitations in terms of its physicochemical properties. Herein, using structure-directing agents, the bayberry-like hollow microsphere alumina supports with a hierarchical structure were hydrothermally synthesised from inexpensive raw materials. The surface of the hollow microsphere alumina is a shell structure with plush protuberance formed by rearrangement and self-assembly of spindle-like nanoclusters. In addition to having a large specific surface area, the microspheres also possess suitable surface acid-base sites. The KMo/Al₂O₃ catalyst for the hydrogenation of CS₂ to CH₃SH was prepared by loading the active component potassium and molybdenum (KMo). The characterization and catalytic performance of catalysts indicate that the hollow microsphere alumina supports can not only improve the dispersion of the active component KMo on its surface but also increase the Mo coordination unsaturated sites on the surface of catalysts, which is beneficial to the activation of CS₂ and the improvement of CH₃SH selectivity. This research can be used as both a theoretical basis and a practical guide for the reasonable design of novel alumina materials and high-performance methanethiol catalysts.