Abstract: Dehydroacetic acid (DHA, Dehydroacetic), also known as diacetyl acetoacetic acid, is solid or white or light yellow crystalline powder, odorless, tasteless, melting point 108 ～ 110 ℃, boiling point 270 ℃ Antifungal agent. It has a certain antibacterial effect under acid and alkali conditions, especially the strongest inhibitory effect on mold. China has been used as a food preservative since the mid-1970s. It has been used as a preservative in foods such as fruit juices, pickles, fermented bean curd, margarine, lactic acid bacteria beverages, and jams [1]. Although its antibacterial effect is effective, its disadvantage of greater toxicity limits the widespread use of dehydroacetic acid. Dehydroacetic acid can be quickly absorbed by the human body, and is dispersed in plasma and many organs after entering the human body, and has the effect of inhibiting various oxidases in the body. At present, the safety of dehydroacetic acid has been questioned, and its use has been explicitly banned internationally. China allows its use within a certain range, but the maximum allowable amount is 0.3g / kg [2]. At present, the national standard method for detecting dehydroacetic acid is gas chromatography [3]. The preliminary sample processing process involves organic solvent extraction, concentration and other steps, which is troublesome to operate, and dehydroacetic acid is also likely to cause tailing of chromatographic peaks, making It is difficult to obtain accurate qualitative and quantitative results [4]. Methods for the determination of dehydroacetic acid in food by high performance liquid chromatography have been reported. For example, ultrasonic extraction, sodium hydroxide solution immersion and other methods are used to extract dehydroacetic acid from moon cakes and then injected into the chromatography column for separation and determination [5]. These studies have done exploratory work for the determination of dehydroacetic acid in liquid foods such as juice, canned, bottled fermented bean curd, etc. by high performance liquid chromatography. This research is in the national standard GB / T5009.121 Ningbo Yinzhou Hengxi Winbate Household Product Manufacturer , https://www.winbatehousehold.com