Environment-friendly vacuum quenching oil and preparation method thereof

The invention discloses environment-friendly vacuum quenching oil and a preparation method thereof. The environment-friendly vacuum quenching oil is prepared from the following raw materials in parts by weight: 72-88.7 parts of base oil, 1-5 parts of polyisobutylene succinimide, 1-5 parts of petroleum sodium sulfonate, 8-15 parts of chlorinated paraffin, 0.5-1 part of sulfide molybdenum dialkyldithiocarbamate, 0.1-0.5 part of 4,4'-methylene bis(2,6-di-tert-butylphenol), 0.1-0.3 part of 2,6-ditertbutyl p-cresol, 0.1-0.2 part of poly-dimethyl silicone oil and 0.5-1 part of dodecenylsuccinic acid. The environment-friendly vacuum quenching oil is tasteless and nonpoisonous, has high oxidation resistance and heat stability, is capable of ensuring that workpieces cannot be oxidized when the workpieces are heated and quenched under high vacuum degree, is also capable of quenching steel to be greater than HRC65 in a wide range under low pressure, and is suitable for quenching large-sized and medium-sized aviation str