Objective To improve the magnetic properties of silicon steel. Methods FeSi alloy coatings with high-silicon content were deposited on the surface of common grain-oriented silicon steel by cathodic arc plasma evaporation, and then a kind of high silicon gradient steel was prepared. The morphologies, content and magnetic properties of the samples were tested. Results FeSi alloy coatings were featured with compact microstructures and excellent adhesive quality with the substrates. The silicon content was 11. 0% ( weight percent) in the surface of coatings, and then the whole sample showed a gradient distribution of silicon. The silicon content was still as high as 6. 5% at a distance of 20 μm from the surface. The resistivity ρ, magnetic properties P_{10 / 50}, P_{10 / 1k} and B₈of the samples were 68. 6 μΩ·cm, 0. 82 W / kg, 83. 3 W / kg and 1. 73 T before annealing. After annealing, the abovementioned four indexes became 63. 1 μΩ·cm, 0. 44 W / kg, 54. 38 W / kg and 1. 89 T. Conclusion The low-frequency magnetic properties of substrates were improved with high resistivity, tensile stress and good crystallinity in high-silicon FeSi alloy coatings, and the high-frequency magnetic properties still need to be improved in future work.