A preparation method for a ceramic watchcase comprises the steps that yttria-stabilized zirconia powder and a surface active agent are weighed proportionally, ethyl alcohol is added, then ball milling mixing is performed, and drying and screening are performed to obtain a sizing agent, wherein the mass ratio of the surface active agent to the yttria-stabilized zirconia powder is 1-5:100; the sizing agent and a binding agent are mixed, and mixing and pelleting are performed to obtain feed for injection, wherein the binding agent comprises polyethylene glycol, oxidized high-density polyethylene, polyvinyl butyral and stearic acid; injection molding is performed on the feed to obtain a green body; the green body is placed into water for water degreasing, and thermal degreasing is performed to obtain a workblank; the workblank is sintered to obtain a semi-finished product; the semi-finished product is machined and polished to obtain a ceramic watchcase. The preparation method for the ceramic watchcase can ensure that the obtained ceramic watchcase has the high strength and is not likely to be broken into pieces, the density is high, holes are uniform, the preparation technology is simple, operation is easy and the production efficiency is high.