Antibacterial anti-corrosion plays a vital role in food preservation and storage, natural antibacterial substances have the advantages of safe, non-toxic and harmless, in recent years has been widely concerned at home and abroad. Shell polysaccharide is a non-toxic and tasteless natural substance, is a crustacean after deacetyl reaction products, with good bioaccumability and biodegradability, at the same time has good antibacterial activity. The molecular weight of shell polysaccharides ranges from several thousand to hundreds of thousands, and studies have shown that crustaceans with a adhesive molecular weight of about 1.5x105 have strong antibacterial activity. At present, it has been applied to shell polysaccharide coating agent, shell polysaccharide fungicide, functional fiber, pesticide reliever, plant growth promoter, soil improver, biodegradable shell polysaccharide film, shell polysaccharide vegetable preservation agent, etc. Dandelion genus chrysanthemum perennial herbs, dandelion plants contain dandelionol, dandelion, choline, organic acid, chrysanthemum and other healthy nutrients, with broad-spectrum antibacterial effect, pneumococcal, meningococcal, diphtheria, echinococcus, dysentery, typhoid bacteria and other strong antibacterial activity. Because different antibacterial agents have different antibacterial mechanisms, combined use, can play their respective antibacterial properties, the antibacterial activity of different microorganisms to form complementary, improve the overall antibacterial activity, the current preservation of compound antibacterial agents has been studied and applied. Therefore, this topic studies the antibacterial activity of shell polysaccharides and dandelion extracts with a adhesive molecular weight of 1.5 x lO5 on E. coli (E. cold, Salmonella), Staphylococcus aureus (S.aureus), and uses the two together to study its antibacterial effect, providing reference and basis for the development of new natural anti-corrosion materials and antibacterial preservation methods. Changes in the diameter and bactericidal rate of the antibacterial ring are known, and the link between crustacean and dandelion extract can produce stronger antibacterial activity than the use of a single antibacterial agent. Combined with table 2 and table 3 analysis, it can be found that in solid medium, shell polysaccharides are much smaller than the diameter of the antibacterial ring produced by dandelion extraction, with a difference of 2.5 to 5.3 times. In liquid bacteria suspension, the difference in antibacterial rate is relatively small, shell polysaccharides on E. coli and Staphylococcus aureus inhibition rate is stronger than dandelion extract. This is due to the high viscosity of shell polysaccharides, not easy to spread in solid mediums, and in the solution of bacteria suspension, shell polysaccharides fully dissolved and dispersed, the activity of antibacterial bacteria can be fully developed. Because the two antibacterial agents have different antibacterial mechanisms, the effective gene N of shell polysaccharides can form a negative charge environment with the bacterial cell wall, hindering the normal flow of substances inside and outside the cell, and some through osmosis through the porous cell wall, destroying the collosus state of the cytostic contents. Dandelions have a strong destructive effect on the cell membranes of bacteria, causing in-cell material to seep out and cause bacteria to die and close. Therefore, after the two antibacterial agents can play their own anti-bacterial action, anti-bacterial activity exceeds the antibacterial activity of a single antibacterial agent.