Micro-/nanostructured materials can control the diffraction and propagation of light, thereby providing new optical properties that can be exploited to enhance photocatalytic processes. In this work, a series of the cauliflower-like MoS2/CdS hybrid micro-/nanostructures is synthesized. These structures contain numerous cracks and pores that can enhance the absorption and utilization of light as well as shorten the distance for transferring photogenerated electrons to the catalyst surface. The results of ultraviolet-visible diffuse reflectance absorption spectra show that the composite material has enhanced absorption in the visible light region. Further investigation of the optical characteristics of the synthesized materials using a finite-difference time-domain (FDTD) simulation reveals that the cauliflower-like micro-/nanostructure increases the optical absorption intensity at the MoS2/CdS interface. Notably, the MoS2/CdS hybrid micro-/nanostructures exhibits high photocatalytic hydrogen production activity (9.5 mmol g(-1) h(-1)) and long-lasting cycle stability. This work helps us to further understand the enhancement mechanism of light absorption and utilization by porous structural materials. (C) 2021 Elsevier Inc. All rights reserved.