Preparation process of high-purity crocetin

The invention belongs to the technical field of natural pharmaceutical chemistry, and relates to the technical field of extraction and separation of active ingredients of natural plants, in particular to a preparation process of high-purity crocetin, which comprises the following steps: (1) deep eutectic system assisted extraction; (2) filtering to remove impurities; (3) alkaline hydrolysis; (4) acid precipitation; (5) pulping and impurity removal; and (6) drying under reduced pressure. Compared with a traditional process, the process utilizes a hydrogen bond formation mechanism, and hydrogen bond receptor betaine is added, so that the hydrogen bond receptor betaine and the target extract crocetin form a deep eutectic system, dissolution of crocetin is promoted, and the extraction rate is increased. In addition, the process is simple in step operation, short in production period and stable in preparation process route, and a large amount of impurities are removed in the pulping step, so that the high-purity c