Low sulfur diesel lubricity additive and preparation method thereof

The invention discloses a low sulfur diesel lubricity additive, belonging to the field of organic synthesis. The additive is characterized by being alkoxy polyethylene glycol glycerin monoether with the structural formula of RO(CH2CH2O)nCH2CHOHCH2OH, wherein R is straight-chain paraffin of C6-C20, and isoparaffin thereof, and n is 1, 2, 3 and 4. The addition amount of the additive provided by theinvention in diesel is generally within the range of 10-1000 mug/g, preferably 100-200 mug/g, and the additive can obviously improve the lubricity index of the diesel and ensure that the lubricity index of the diesel (on a HFRR (High Frequency Reciprocating Rig)) is in accordance with the requirement of a diesel standard in China, namely, the HFRR wear scar diameter of the diesel is not larger than 460 micrometers. Meanwhile, the invention provides a preparation method of the additive.