The invention relates to a method for preparing zirconium oxide ceramic, which comprises the following steps of: preparing high solid phase slurry by adopting low-toxicity gel and dispersant, then adding an initiator, performing vacuum deaeration, injecting the slurry into a mold, curing and stripping to obtain a green body, and drying and sintering the green body to obtain the ceramic. The method is used for preparing the green body which has good surface finishment, peeling resistance, cracking resistance, good uniformity and high strength, the strength of the green body is 20 to 40MPa, andthe green body can be directly machined so as to effectively reduce the subsequent processing cost; and the green body can be sintered into the ceramic at one time, the yield reaches 100 percent, theceramic has excellent performance and good stability, the strength is 800 to 1,200MPa, the fracture toughness is 10 to 20MPa.m1/2, the average strength is 550MPa compared with the strength of the drypressing molded ceramic, the average fracture toughness is 8MPa.m1/2, and the performance of the ceramic is greatly improved.