High purity oleic acid is an important fine chemical products. Selective hydrogenation of fatty acid in the chemical industry is a very important aspect, but also the production of high-purity oleic acid and reasonable way. Raney nickel catalyst for selective hydrogenation of mixtures of orthogonal test and the single factor level testing, the product is freezing point determination and after Webster's method for determination of iodine value optimum reaction conditions: at a temperature of 200 ° c, pressure up to 0. Omega 6MPa, 1h, catalyst (b) =0. 6%, mixing 250R/min can make mixing and iodine value of fatty acids from 120. 84 per cent to 100 per cent, before and after freezing point changes little, improve the purity of oleic acid.