The invention discloses a preparation method of a mobile telephone shell. The preparation method comprises weighing yttrium oxide-stabilized zirconia powder and a surfactant according to a mass ratio of the surfactant to yttrium oxide-stabilized zirconia powder of 1-5: 100, adding ethanol into the weighed materials, carrying out ball milling mixing, carrying out drying and sieving to obtain slurry, mixing the slurry and a binder, carrying out mixing and granulation to obtain feed for injection, wherein the binder comprises polyethylene glycol, oxidizing high density polyethylene, polyvinyl butyral and stearic acid, carrying out injection molding on the feed to obtain a green body, carrying out staining detection on the green body, putting the green body into water, carrying out water debinding, carrying out thermal debinding to obtain a blank, sintering the blank to obtain a semifinished product, and carrying out machining and polishing on the semifinished product to obtain the mobile telephone shell. The mobile telephone shell has high strength, is not easily broken and has high density and uniform apertures. The preparation method has simple processes, operation easiness and high production efficiency.