Sodium dehydroacetate is a broad-spectrum food preservative with extremely strong antibacterial power, and it has a particularly strong inhibitory effect on molds and yeasts. Under the same addition amount, the antibacterial effect is several times or even dozens of times higher than that of the widely used sodium benzoate and potassium sorbate at present. What is particularly valuable is that it has a very small inhibitory effect on acid-producing bacteria, especially lactic acid bacteria. In accordance with the relevant national standards and the recommendations of the US FCC, it is applicable to fermented bean curd. Anti-corrosion and anti-mold for products such as assorted pickles, kimchi, sauerkraine, original fruit juice, concentrated fruit juice, fruit wine, cheese, cream, margarine, yogurt, lactic acid beverages, carbonated beverages, red bean paste, bread, mooncakes, pastries, sweet bean sauce, canned food, condiments, health products, cosmetics, etc.