<p>The activation effect of a new activator MF named after manganese oxide and fluorine on direct acid leaching vanadium from clay vanadium ore was investigated from the electrochemical perspective by measuring open circuit potential (OCP), potentiodynamic polarization curve (Tafel), and electrochemical impedance spectroscopy (EIS). The results indicated that when the mass ratio of manganese oxide to fluorine was 25%:75%; the OCP, Tafel corrosion potential, and charge transfer impedance were lower; and the corrosion current density reached the maximum, which testified that clay vanadium ore was more easily corroded and dissolved. Compared with the non-activated acid leaching system, the OCP, Tafel corrosion potential, and charge transfer impedance decreased, and the corrosion current density enhanced during acid leaching with activator MF. In addition, the oxidation dissolution efficiency of clay vanadium ore was accelerated by increasing the dosage of activator MF from 1 to 3%. Meanwhile, scanning electron microscopy (SEM) and surface area analysis showed that the surface of activated acid leaching residue was loosened and porous, the structure was looser, and the specific surface area was larger. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that the mineral structure of clay vanadium ore was destroyed to a greater extent in the activated acid leaching with activator MF.</p>