Polycyclic aromatic hydrocarbons (PAHs) are of increasing concern due to their environmental persistence, toxicity, and potential for bioaccumulation. In this study, the Ag3PO4/MoS2 composite catalyst with a 10% MoS2 mass fraction exhibited the highest catalytic activity for the degradation of Phe, Pyr, and BaP, with degradation rates of 99.7%, 99.4%, and 96.9% under optimal degradation conditions, respectively. The effects of pH, catalyst dosage, and PAH concentration on the catalytic degradation of PAHs were investigated, and the underlying mechanisms were elucidated. The study of the contribution values of catalytically active species suggested that h(+) and O-2(-) active species were the primary contributors to the degradation of PAHs, indicating a photogenerated carrier transfer mechanism in the coexistence of heterojunction and Z-type systems. The degradation intermediates were detected by high-resolution mass spectrometry (HRMS), and possible degradation pathways and mechanisms for the photocatalytic degradation of PAHs were proposed. Cycling tests demonstrated that the catalytic degradation of Phe (800 mu g/L) remained at 93.5% after four consecutive cycles of the catalyst. [GRAPHICS] .