The invention provides an emulsified oil composition which comprises the following components in parts by mass: 67-72 parts of 25# mechanical oil, 2-2.5 parts of chlorcosane, 3-6 parts of petroleum sodium sulfonate, 7-10 parts of OP-10, 3-5 parts of octyl phenol polyoxyethylene ether, 6-9 parts of sorbitol anhydride trioleate, 0.2-3 parts of potassium hydroxide, 1-3 parts of oleic acid and 0.5 parts of water, wherein petroleum sodium sulfonate has strong hydrophilism, has a corrosion inhibition effect on metal and also has good anti-rust effect. OP-10 and octyl phenol polyoxyethylene ether both have good emulsifying and cooling effects. Octyl phenol polyoxyethylene ether can be further used as a reducer to remove copper oxide, so as to prevent a copper rod from being oxidized. Due to use of Chlorcosane, the emulsified oil has good mobility and cooling performance. Oleic acid has the polishing and rust-removing effects. The 25# mechanical oil has a certain cooling effect.