The study examines the corrosion behavior of the (NdSmEuGd)(1-x)/2Dy2xZr2O7 series in 1300 °C molten salt CMAS, demonstrating that the dense layer formed by ZrO2 and apatite could effectively inhibit the penetration of CMAS. Smaller rare-earth ion radii tend to form larger-sized ZrO2, while larger rare-earth ion radii favor apatite formation. Therefore, by carefully balancing the rare earth ion radii in the composition design of high-entropy samples, the levels of ZrO2 and apatite formation can be adjusted to prevent CMAS infiltration. This approach helps identify high-entropy zirconate samples with superior corrosion resistance to CMAS.