In this work, AlCoCrFeNiCuSi x (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) high-entropy alloy plasma cladding coatings were prepared on the surface of 35CrMo. The regulation mechanism of Si doping on the microstructure and properties of the coatings was investigated. The research results show that Si doping adjusted the valence electron concentration (VEC) of the coatings from 7.83 to 7.54, driving the transformation from the FCC phase to the BCC/B2 phase. The coatings with Si 0.4 and Si 0.5 mainly comprise the BCC/B2 phase. The BCC phase and the B2 phase are distributed in an inter-lamellar form. Cu - rich nanoparticles and L1 2 phases are precipitated in the B2 and FCC phases, respectively. Both the microhardness and wear resistance of the coatings gradually increase with Si doping. The corrosion resistance of the coatings exhibits a non-linear trend, initially increasing and then decreasing with the increase in Si content. The coating with Si 0.2 exhibits the best corrosion resistance.