oleic acid, monoester with oxybis(propanediol) preparation method: (1) the fatty acid mixture containing oleic acid and urea dissolved in organic solvents, after cooling, the precipitation of crystals separated and removed. (2) The fatty acid mixture in the partially dissolved organic solvent solution was crystallized by recrystallization and filtration. (3) The crystals were acidified to obtain essential oil acid. Glycidol is added to the refined oleic acid, or the oleic acid is esterified with polyglycerol, or the oleic acid and polyglycerol are dehydrated.