Preparation method of food-grade all-cis jasmone

The invention discloses a preparation method of food-grade all-cis-jasmonone, relates to the technical field of all-cis-jasmonone production, and aims to solve the problems of relatively long synthetic process route, relatively low product yield, large waste amount, relatively difficult treatment and the like in the methods in the prior art. According to the method, styrene, chlorine and hydrogen are subjected to hydrochlorination reaction to obtain 1, 2-chlorinated styrene, then the 1, 2-chlorinated styrene is subjected to base catalysis reaction to generate ethylene oxide, the ethylene oxide and sodium chloride are synthesized into sodium ethylene oxide, then aldehyde ketone is generated, and the aldehyde ketone reacts with sulfuric acid to prepare the all-cis-jasmonone, so that high yield is achieved, and meanwhile, the yield of the all-cis-jasmonone is increased. The production cost is reduced; the adopted catalyst is environment-friendly and conforms to the concept of green chemistry; reaction conditions