Method for preparing high-content conjugated linoleic acid through purification of vegetable oil as raw material

Provided is a method for preparing a high-content conjugated linoleic acid product by using ordinary vegetable oil as a raw material. The method comprises three steps of alcoholysis, purification and isomerization of the vegetable oil. The alcoholysis of the vegetable oil comprises preparing corresponding methyl ester or ethyl ester by using glyceride as a raw material; the purification of the methyl ester or ethyl ester comprises performing silvered silica gel column chromatography to obtain methyl linoleate or ethyl linoleate having the content higher than 85%; and the purified methyl linoleate or ethyl linoleate is subjected to alkali-catalyzed conjugation to obtain high-content conjugated linoleic acid, and then, conjugated linoleic acid series products can be prepared according to actual needs. The method addresses the situation that high-content conjugated linoleic acid has been prepared based solely on safflower oil before, broadens the source channel of conjugated linoleic acid, and meanwhile provides a process of efficiently separating and purifying linoleic acid; the obtained conjugated linoleic acid has high purity and meets the requirements for application in industries such as pharmaceuticals and health care products.