Abstract: The working blades of a certain engine's high-pressure turbine are made of nickel-based single crystal superalloy. To enhance their high-temperature corrosion resistance, the blade surface is coated with a NiCrAlY+AlNiY composite coating using arc ion plating technology. After the engine test run, peeling occurred on the surface of the blade body. Through macroscopic and microscopic inspections, combined with the engine disassembly, an analysis was conducted on the peeling failure of the high-pressure turbine working blade surface. The cause of the failure was found to be wear and tear of the sealing coating on the inner side of the compressor working ring. The peeled coating adhered to the blade's suction side after high-temperature oxidation, forming a grayish-black deposit.