Three-dimensional spherical Sb₂S₃/Sb₄O₅Cl₂ microcrystallines were synthesized for the first time via a facile hydrothermal process without any oxychlorides at 100 °C. The powder X-ray diffraction pattern showed that the product corresponded to the Sb₂S₃/Sb₄O₅Cl₂ composites. The combination of the product was further confirmed by X-ray Photoelectron Spectroscopy (XPS), energy dispersive X-ray (EDX) and high-resolution transmission electron microscopy (HRTEM). Scanning electron microscopy (SEM) studies revealed that the irregular shaped nanoblocks self-organized into spherical assemblies. The suitable temperature, the possible mechanistic pathway in the formation of the structures and the mechanisms are discussed. Moreover, the as-prepared materials also had an excellent visible light photoactivity for methyl orange (MO) degradation, and could remove 82.9% MO in 60 min.