CdS nanocrystals (NCs) is a very important visible-light-driven photocatalyst due to their optimal band gap of 2.4 eV, but their photocatalytic performance is still restrained by a few factor such as easy aggregation and weak response to UV light. In this work, we employ spindle-like GdBO3:Ce,Tb particles as seeds to grow some CdS NCs on their surface. In the prepared GdBO3:Ce,Tb/CdS composite photocatalysts, the GdBO3:Ce,Tb particles not only serve as a substrate to improve the stability of CdS NCs but also work as a light-transducer to convert the UV light to visible emissions to activate the CdS NCs. In contrast to pure CdS NCs, the hybrid photocatalyst exhibit an enhanced photocatalytic performance due to the additional utilization of the UV light and the substrate effect. The hybrid photocatalysts have been characterized by XRD, TEM, and PL etc. and their working mechanism has been elucidated. Graphical Abstract [GRAPHICS] .