High-performance yttrium oxide and phenolic resin (Y₂O₃-PF) alternating coating is prepared on epoxy resin based composite material using supersonic plasma spraying and dual-channel powder feeding technology. In the experiment, Y₂O₃ coated PF powder is sprayed onto substrate to fabricate a transition layer, and then spherical Y₂O₃ powder and Y₂O₃ coated PF powder are alternately deposited to form a composite alternating coating. The average bonding strength between as-prepared coating and substrate is as high as 26.48 MPa, with a maximum strength value of 28.1 MPa and shear strength of 24.30 MPa. The main body of alternating coating is formed by depositing the mixture of PF powder and Y₂O₃ powder wrapped around it. Furthermore, the heat transfer effect generated by heating external Y₂O₃ particle gradually softens and melts PF, thus effectively avoiding the damage of high temperature to molecular structure. As a result, it promotes the crosslinking and curing effect of resin during the deposition process. In addition, the unmelted Y₂O₃ powder effectively promotes shot peening action, which washes out the powder particle with poor deposition effect, ultimately improving the physical and chemical properties of as-prepared alternating coating.