In the present work, the high-velocity oxygen fuel spraying technology was used to fabricate the (AlCoCrFeNi)x/(WC-10Co)1-x x = 100 (C1), 75 (C2), and 50 (C3) wt% composite coatings and the 316 stainless steel was used as substrates. The main BCC phase and the minor FCC phase were primary components of the AlCoCrFeNi coating. The average hardness of the C1, C2 and C3 coatings was 646 HV0.2, 741 HV0.2, and 823 HV0.2, respectively. After being eroded for 15 h, the average hardness of the eroded coatings increased. WC enhanced the erosion performance and significantly decreased the volume loss of the coatings. The volume loss rate of the coatings decreased with the erosion process owing to both the dislocation strengthening of high-entropy alloy (HEA) and embeddedness of WC. For the AlCoCrFeNi coating, the erosion mechanism consisted of a mainly ductile failure such as cutting, plowing and removed squeeze lip, and a minorly brittle failure, in which crack and spalling of BCC phase appeared. The primary erosion destruction mechanism of WC in the composite coatings was brittle fatigue wear since crack and spalling contributed to the erosion damage of WC. The ductile removal of WC was also observed in this work, such as micro-scratch. •The (AlCoCrFeNi)x/(WC-10Co)1-xcomposite coatings were bonding well with the substrates by applying HVOF spraying technology.•The addition of WC significantly improved the erosion performance of AlCoCrFeNi coating.•The volume loss rate of coatings decreased with the erosion process by the dislocation strengthening.•The erosion mechanism of the (AlCoCrFeNi)x/(WC-10Co)1-x composite coatings was studied.