The work aims to study the eroded morphology, erosion mechanism and erosive wear properties of the FeCoCr0.5NiBSix high-entropy alloy at high temperature. The FeCoCr0.5NiBSix (x=0.1~0.4) high-entropy alloy coating was pre-pared on 45 steel substrate by laser cladding. The high-temperature erosion tests were performed to the FeCoCr0.5NiBSix coating with different Si content at room temperature and 650~900 ℃ respectively. The cross section and eroded surface morphology of the FeCoCr0.5NiBSix coating were analyzed by SEM and EDS. The microhardness and erosion rate of the coatings were also measured. The FeCoCr0.5NiBSix coating was composed of simple FCC solid solution and boride, and the Si element was easy to be dissolved in the FCC solid solution. The erosion morphology of the FeCoCr0.5NiBSix coating was dominated by ploughing and cutting at low impact angles, while the indenting morphology appeared at high impact angle. With the increase of Si, the hardness of FeCoCr0.5NiBSix coating decreased first and then increased, which was opposite to the erosion rate of the coating at low impact angle, and was consistent with the law at high impact angle. The erosive wear law of the FeCoCr0.5NiBSix coating was exactly opposite to that of 304 stainless steel, and the erosion rate of the FeCoCr0.5NiBSix coating increased with the increase of impact angle and erosion temperature. The minimum erosion wear rate of the FeCoCr0.5NiBSix coating was 8.2 mg/cm2 at impact angle of 30°. The erosive wear mechanism of the FeCoCr0.5NiBSix coating is similar to that of brittle materials, namely the cutting and ploughing damage at low impact angle, and the extrusion damage and brittle fracture at high impact angle. The erosion rate of the FeCoCr0.5NiBSix coating is obviously better than that of 304 stainless steel at low impact angle.