The invention belongs to the technical field of preparation of new-material rings, and relates to a preparation method of a ceramic ring. The preparation method comprises the technology process with the following steps of slurry preparation, blank forming and microwave sintering. The high-density, uniform and dense ceramic ring is prepared from the slurry with high solid phase content and good fluidity through net size liquid casting in-situ condensing forming and microwave sintering, the density is 6.02g/cm<3>, the hardness is 12.23GPa, the bending strength is 896.86MPa, and the breaking toughness is 11.36Mpaml/2. The preparation method has the advantages that the metal ring in the prior art is completely replaced; after sintering, the ceramic ring can be used by as long as the surface is polished, so that the grinding procedure after sintering is avoided; the abrasion-resistant property, size stability, self-lubricating property and polishing property are good, the friction coefficient is small, and the ceramic ring is used for replacing the alloy ring in the yarn production; the principle is scientific and reasonable, the operability is strong, the energy consumption is low, the investment is small, the rate of finished yarns is high, the preparation cost is low, the environment-friendly effect in use is realized, and the good industrial application prospect is realized.