TiCrAlNbSi alloy coating is a high-temperature corrosion-resistant material. This study investigates the method of preparing high-entropy TiCrAlNbSi alloy coating on Ti6Al4V substrate and evaluates its high-temperature oxidation performance. The experiment uses an alloy target and Si target magnetron sputtering method to prepare TiCrAlNbSi alloy coating, optimizes sputtering power and other process parameters, and characterizes the structure and high-temperature resistance of the coating. The results show that the coating is dense and uniform with smooth surface, and has the characteristics of high entropy composition. In the high-temperature oxidation test, the coating exhibited good oxidation resistance, and the oxide product was dense and uniform, without obvious peeling and falling off on the surface of the coating. In summary, the method of magnetron sputtering to prepare high-entropy TiCrAlNbSi alloy coating on Ti6Al4V substrate has good high-temperature oxidation performance and has application prospects.