Photocatalytic activity of the composite photocatalyst AgBiO3/BiOCl was examined after the interface of AgBiO3 was modified by growing BiOCl in situ and building heterojunction towards increasing reactive oxygen species (O⁎) and oxygen vacancy (OVs) production. The degradation of rhodamine B (RhB) revealed that the photocatalytic performance of the heterojunction structure of AgBiO3/BiOCl-x (x=0.05, 0.2, 2, 5) was significantly improved over that of AgBiO3 monomer, with the degradation effect of AgBiO3/BiOCl-2 reaching 99.6% within 60minutes and no significant decrease in performance after reuse (93% degradation after four cycles). Similar experiments also used another contaminant, tetracycline hydrochloride (TC-HCl). Within 60minutes, under visible light irradiation, the degradation rate of TC was 89.1% and the degradation rate was 0.0367min-1. The effects of catalyst addition, varied starting concentrations, and pH on RhB degradation were also studied. Furthermore, the free radical scavenging studies and chemical characterizations revealed that the principal reactive radicals functioning in the reaction system were h+, 1O2 and ‧O2-. Based on the findings, a potential catalytic mechanism for the synergistic degradation of RhB via photo-driven and chemical oxidation of AgBiO3/BiOCl heterostructures was postulated.