The invention provides a preparation method of a high-temperature creep-resistant ceramic material, which comprises the following steps: S1, weighing 50-90 parts by weight of high-purity alpha-Al2O3 powder, 25-50 parts by weight of tabular corundum powder, 1-3 parts by weight of zirconium oxide powder and 0.5-1 part by weight of sintering aid, taking water as a solvent, adding a water-soluble dispersant, and carrying out ball milling to obtain slurry; s2, carrying out vacuum defoaming on the slurry, adding a catalyst and an initiator, uniformly stirring, injecting into a mold, curing, and demolding to obtain a green body; s3, drying the green body, softening, cutting into green sheets, and drying; and S4, sintering the dried blank sheet to obtain the ceramic material. The bulk density of the powder of the raw material components in different parts by weight is high, and the prepared ceramic material is a high-density material with high density and high hardness; and through mutual cooperation and distribution of the raw material components, bridge support of tabular corundum in a material system, and phase change toughening of alpha-Al2O3 and zirconium oxide in a high-temperature stage, and the prepared ceramic material has improved high-temperature creep resistance, breaking strength and erosion resistance, and is not easy to break and long in service life.