In oil and gas industries, erosion wear presents a major problem in the hydraulic fracturing process and severely reduces the erosion life of tools. Tungsten carbide (WC)-based high-velocity oxygen-fuel (HVOF) thermal spray coating is widely applied to improve surface properties. However, the erosion wear mechanism of this coating in liquid-solid two-phase flows is not clearly understood. Therefore, in this study, the HVOF thermal spray WC-based coating was characterized, and the erosion behavior of the coating was studied in a wet erosion test rig. Results showed that the experimental parameters, namely, attack angle, impact speed, particle size, and erosion time, exerted significant effects on the erosion rates of the specimens. The coated specimens exhibited higher hardness and better erosion wear resistance than the uncoated substrate due to the hard phase particles of the coating. The surfaces of the coated specimens showed microcutting, craters, and brittle chipping, as a visible manifestation of material removal. Furthermore, the erosion wear mechanism of the deposited coating was established by analyzing the eroded morphologies. The findings of this study can help enrich the understanding of the erosion wear mechanism of WC coatings in liquid-solid two-phase flows. (C) 2017 Elsevier B.V. All rights reserved.