A preparation method of a zirconia ceramic slice comprises the following steps: providing stable tetragonal phase zirconia powder, rare earth oxide powder, a solvent, a dispersant, an ultraviolet initiating agent, a photosensitive polymeric monomer and an assistant; mixing the tetragonal phase zirconia powder, the rare earth oxide powder and the solvent, performing ultrasonic dispersion agglomeration operation, and then performing evaporation to remove the solvent, thus obtaining mixed powder; mixing the mixed powder, the dispersant, the ultraviolet initiating agent, the photosensitive polymeric monomer and the assistant, and then performing ball-milling and bubble removing operation, thus obtaining zirconia ceramic slurry; adding the zirconia ceramic slurry into a ceramic casting machine, and then enabling a base plate of the ceramic casting machine loading the zirconia ceramic slurry to pass through an ultraviolet curing machine, thus forming a zirconia ceramic slice green body; sintering the zirconia ceramic slice green body, thus obtaining the zirconia ceramic slice. By adopting the preparation method, a conventional drying process can be avoided, and a prepared product is enabled to have better quality.