In this work, CdS/Ti-32-oxo-cluster (CTOC) composites were first synthesized via in situ precipitation and ultrasonic methods. The experimental results demonstrated that CdS nanoparticles uniformly decorated the surface of CTOC with high specific area and microporous to form composite structures. Meanwhile, the CdS/CTOC composites exhibited an excellent high rate of photocatalytic activity for tetracycline hydrochloride (TC) degradation under visible light irradiation, and the activity performance was approximately 4.49 and 16.36-fold higher than that of pure CdS and CTOC, respectively. Moreover, The Ti3+ signal was detected by electron paramagnetic resonance (ESR) technique after irradiation, and the superoxide radical (O-center dot(2)-) and holes (h(+)) were proven to be the main active species during the degradation of TC. Photocatalytic mechanism and intermediates over CdS/CTOC composites were elucidated and corresponding reaction model and degradation routes of TC were presented. It is anticipated that this work could boost new insight on CdS/ CTOC binary composite systems to effectively degrade organic pollutants, which given a strategy for application on practical industry.