A novel flower-like ternary Fe₃O₄-magnetic quantum dots / Bi₂WO₆/ Graphene nanosheet (Fe₃O₄− MQDs /Bi₂WO₆ / GNs) composite was successfully prepared by a facile one-pot hydrothermal method. The prepared samples were characterized by XRD, FTIR, UV–vis, SEM, HRTEM, EDS, BET and VSM technologies. Compared with the Bi₂WO₆ and Fe₃O₄/Bi₂WO_6, the Fe₃O₄/Bi₂WO₆/GNs catalyst exhibited higher  photodegradation  ratio of 98.2% for methylene blue (MB) and 90% for Tetracycline hydrochloride (TC) within 210 min irradiation at pH 7, and stability over 80% even after six cycles. Characterization results showed that the enhanced photocatalytic activity was mainly due to the strong interactions of MQDs/Bi₂WO₆heterojunction and high specific surface area. A possible photocatalytic degradation mechanism was proposed on the basis of the identified intermediates. Furthermore, the Fe₃O₄/ Bi₂WO₆/ GNs composite could be easily recovered from the reaction system under an external magnetic field owing to its sufficient magnetism, therefore which has certain potential applications in water treatment process.