Oxytetracycline (OTC), as one of the most used antibiotics, is ubiquitous in aqueous environment and considered as a worldwide issue. In the study, the photocatalytic degradation of oxytetracycline was investigated. A novel composite of 15% TiO2/13X (15%T13X) as photocatalyst was synthesized with TiO2 and 13X zeolite. Moreover, the adsorption of OTC by 15%T13X and TiO2 was individually investigated. Besides, OTC photodegradation with pH was studied and an optimum of 9 was reached, and the influence of radical scavengers and humic acid were also investigated. The mineralization and toxicity change during photocatalytic processes was detected by TOC analyzer and standardized by bioluminescence assay on Vibrio qinghaiensis sp.-Q67 (Q67). The results showed that the composite of 15%T13X had better performance in photodegradation and detoxification than TiO2 because of its combined effects of adsorption and photooxidation. Overall, it is concluded that the composite photocatalyst of 15%T13X was effective in treating oxytetracycline in aqueous solution.