Reported here is a pioneering work on the co-removal of carbamazepine (CBZ) and metronidazole (MNZ) by Co₂AlO₄@Al₂O₃ millispheres activated peroxymonosulfate (PMS). Compared with the single removal, the reduced ratios for the removal kinetics of MNZ (72.16%) are two times higher than that of CBZ (35.41%) within initial pH 3 – 9. This is essentially due to the higher oxidation affinity of SO₄^– and ¹O₂ toward CBZ than MNZ. Cl^- facilitated the degradation of CBZ but inhibited the degradation of MNZ, probably ascribed to the formation of HOCl and Cl₂^-. HCO₃^- and PO₄^3- significantly inhibited the removal of CBZ and MNZ by scavenging SO₄^– and/or passivating the active sites of Co₂AlO₄@Al₂O₃. The degradation of CBZ is mainly due to the electron abstraction and oxygen addition, while the primary oxidation processes of MNZ include the denitration, ring opening and/or N-C cleavage. Because of the competition of CBZ against SO₄^-, the simultaneous removal process remarkably changed the main products of MNZ compared with the single removal process. The simultaneous removal of CBZ and MNZ increased the total bioaccumulation potential and mutagenicity risk of degradation products but helped to reduce their total developmental toxicity. The products formed in the co-removal process showed higher total acute toxicity to Daphnia magna than those of the single process, while for the total acute toxicity to Oral rat, the results are reversed. This work will spark more interest of simultaneously removing multiple emerging pollutants with monolithic catalysts-oriented oxidation processes.