Application： 1.It can be used as anticorrosive and mildewproof agent for pastry, soybean products, dumpling skin, wonton skin, raw cut noodles, cheese, etc. In the processing process of bayberry canning, it is used for soaking bayberry. Used in beer production can inhibit the formation of adverse viscous substances. 2. sodium propionate liquid wet acid preservative, its antibacterial effect is affected by environmental PH. The minimum inhibitory concentration was 0.01% at PH5.0 and 0.5% at PH6.5. In the acidic medium, it has a strong inhibitory effect on all kinds of molds, aerobic bacillus and gram-negative bacillus. It has special effect on preventing the production of aflatoxin, but has almost no effect on yeast. In addition, it is also used as a preservative for food. 3. in the tannery as a masking agent, in order to improve the alkali resistance of leather and tanning uniformity. 4.sodium acid is also an acid food preservative, its antibacterial effect is affected by the environmental pH value. The minimum inhibitory concentration is 0.01% at pH 5.0 and 0.5% at pH 6.5. In acidic medium, it has strong inhibitory effect on all kinds of molds, gram-negative bacilli and aerobic bacillus. It has special effect on preventing the production of aflatoxin, but has almost no effect on yeast. In the food industry, it can be used for the preservation of pastries, the amount of 2.5g/kg(calculated by propionic acid, the same below); The maximum use of 50g/kg in 3% ~ 5% aqueous solution soaking bayberry. It can also be used as an anti-mold agent for feed. 5.food, feed and anti-corrosion, anti-mildew agent. The general addition amount is 0.1-0.3%. 6.Cosmetic preservatives. It has a wide range of antibacterial effects on molds, yeasts and fungi. The antibacterial activity was particularly obvious in acidic hydrolysate.