Tetracycline hydrochloride (TC), as a broad-spectrum antibiotic, is widely used in clinical medicine, animal husbandry, and aquaculture. It makes a large amount of TC wastewater discharged into the aquatic environment and ultimately endangers human health through the food chain. As an advanced oxidation technology, photocatalysis has significant advantages in refractory wastewater treatment. In this study, Bi2WO6 was prepared by the hydrothermal method, and the composite CeO2/Bi2WO6 was synthesized by doping appropriate CeO2 in Bi2WO6. The crystal structure, morphological characteristics, and light absorption performance were characterized. The results showed that the CeO2/Bi2WO6 ratio, catalyst dosage, initial concentration of TC, and initial pH value of the solution had a significant impact on the catalytic degradation of TC by photocatalysis under visible light. The formation of CeO2/Bi2WO6 heterojunction could effectively improve the separation efficiency of photogenerated electron-hole pairs, thereby greatly enhancing photoactivity. When the molar ratio of CeO2/Bi2WO6 was 1:3, the initial pH value was 5, the initial concentration of TC was 8 mg/L, and the dosage of CeO2/Bi2WO6 was 0.4 g/L, the removal rate of TC and TOC of the solution could reach up 90.7% and 64.3%, respectively. The possible photocatalytic degradation mechanism of TC over CeO2/Bi2WO6 was proposed according to the results of the free radical captured experiment and the potential value of the conduction band and valence band of the catalyst. After six cycle experiments, the removal rate of TC by CeO2/Bi2WO6 catalyst could still reach 86.4%.