The work aims to study the effect of Si content on the microstructure and properties of CoCrFeNi high-entropy alloy coating. Preparation of CoCrFeNiSix (x=0.0, 0.5, 1.0, 1.5, 2.0) high-entropy alloy coating on 45# steel substrate by laser cladding technology. The macro morphology, microstructure, microhardness and friction and wear properties of single and multi-layer cladding layer are observed by scanning electron microscopy (SEM), X-ray diffractometer (XRD), microhardness tester and friction wear tester. The research shows that high-entropy alloy coating forms a good metallurgical bond with the substrate, adding an appropriate amount of Si can improve the surface formability of the cladding layer. With the increase of Si content, the microstructure of the coating changes from equiaxed crystals to dendrites, and then to equiaxed crystals. Coating changes from fcc structure to bcc structure.The unit cell structure size decreases and the coating density increases. When x=2.0, the hardness reaches about 600HV0.5, which is about 3 times of the substrate. When the Si content is the highest, the wear amount is the smallest and the friction coefficient is also the lowest, which is about 0.49. Overall, adding Si to CoCrFeNi-based high-entropy alloy can lower the melting point of the alloy, improve the wetting ability, and improve the oxidation behavior of the coating. Si can also increase the nucleation rate of the coating and play a role in grain refinement. Si as an added element also increases the hardness of the coating and improves the wear resistance and friction reduction of the coating.