The work aims to improve corrosion resistance of iron and steel materials. The surface of Q235 steel was electroplated with AlCl3-NaCl-KCl molten salt system taking 1.0%MnCl2 as Mn source when current density was 13.3, 26.7, 48.0, 50.0 and 55.6 mA/cm2, respectively. Cyclic voltammetry curves of the electroplating process in the molten salt system were tested. Surface and cross section of the plating were detected with X-ray diffractometer (XRD), electron spectroscopy (EDS) and scanning electron microscopy (SEM). Potentiodynamic polarization curve test was performed to the plating with electrochemical workstation in 1 mol/L NaCl solution. The aluminum and manganese were co-deposited during the electroplating process. Al-Mn alloy plating obtained at different electroplating current density was amorphous. Cross-section analysis indicated that the uniform plating had clear boundaries and was composed of Al and Mn. At low current density, the plating obtained was flat and smooth. At the current density of 48.0 mA/cm2, cellular-like substance formed in the plating become distinct as current density increased. Equilibrium potential, linear polarization resistance and corrosion current density first increased and then decreased as the current density increased. The minimum corrosion current density and the maximum linear polarization resistance were obtained at the current density of 48.0 mA/cm2. The Al-Mn alloy coating is amorphous, and the plating obtained at the electroplating current density of 48.0 mA/cm2 exhibits better corrosion resistance in 1 mol/L NaCl solution.