The invention discloses hydraulic oil which is prepared by the following raw materials in part by weight: 20 parts of dewaxed oil, 1-4 parts of sodium sulfide fatty acid, 3-5 parts of molybdenum disulfide, 3-6 parts of fatty alcohol-polyoxyethylene ether, 4-7 parts of sodium sulfosuccinate, 1 part of diisooctyl diphenyl, 1.5-2.5 parts of sorbitol, 2-5 parts of sodium tripolyphosphate, 1.2-5 partsof polyisobutene and 2 parts of ethyl carbamate. The hydraulic oil disclosed by the invention is low in cost, hard to emulsify and capable of being used in hydraulic oil stations, jacks, oil cylindersand other equipment.