The invention relates to a preparation method of double-rare-earth-ion tantalite high-temperature ceramic and belongs to the technical field of high-temperature ceramic preparation. The molecular formula of the double-rare-earth-ion tantalite high-temperature ceramic is shown in the description (REa / REb = Y, La, Nd, Sm, Eu, Gd, Dy, Er and Yb, and REa and REb are not the same type of rare earth elements). The used raw materials are rare earth oxide and tantalum oxide andare weighed in proportion, the weighed raw materials and absolute ethyl alcohol are put in a ball milling tank for mixing and sealing, then the mixture is put on a planetary ball mill for ball milling, the mixture can be evenly mixed, and primary sintering is performed after the mixed powder is dried and screened; the cooled and taken-out sample is grinded, ball-milled, dried and screened and then is put in a mold for compaction, and then secondary sintering is performed. The preparation method is high in purity, low in impurity content, low in product device cost and suitable for batch production, and the product is expected to be a novel ceramic material resistant tohigh temperature, oxidation and abrasion.