Abstract: In order to obtain excellent coating materials, FeCrNiMnMoB0.5 high entropy alloy coatings were prepared on Q235 steel by laser cladding. The effect of Mo on microstructure and properties of high entropy alloy coatings have been investigated emphatically. By means of optical microscope, X-ray diffraction, scanning electron microscope, hardness tester and electrochemical workstation, the microstructure, phase structure, hardness and corrosion resistance were studied. Results show that the microstructure of FeCrNiMnMoB0.5 high entropy alloy coatings is dendrites and the coating is mainly composed of fcc phase and a small amount of intermetallic compounds. After adding a small amount of Mo, the average hardness is very low, about 290 HV. With the increase of Mo, lattice distortion is enhanced and metal compounds appear. The hardness of the coating reaches a maximum of 658 HV. Polarization curves indicate that FeCrNiMnMo0.4B0.5 shows good corrosion resistance in the saturated salt mud solution.