In the present study, cobalt-doped bismuth ferrite (Co/BiFeO3) composite was fabricated by sol-gel method, followed by annealing treatment. Afterwards, physicochemical properties of the resulting composite were systematically studied by scanning electron microscope, X-ray diffraction, transmission electron microscope, N-2 physical adsorption/desorption and vibration magnetometer measurements. Results indicated that after doping with Co species, average diameter of BiFeO3 distinctly reduced, accordingly, specific surface area increased, in which Co element existed in the form of Co3O4. In addition, Co/BiFeO3 displayed superior magnetic recovery characteristics. Furthermore, Co/BiFeO3 composite was applied to decompose tetracycline in water by activation of persulfate (PS, S2O82-) via the formation of sulfate radicals. It was found that Co/BiFeO3 exhibited high efficiency for removal of tetracycline, in which 81.09% of tetracycline could be decomposed. This study provides a versatile strategy to fabricate high-efficient recyclable catalysts which would be applied in advanced pharmaceutical waste water treatment.