Multilayer coated drug-loading controlled-release hydrogel and preparation method thereof

The invention relates to the technical field of drugs for plant disease and insect pest control, in particular to multilayer coated drug-loading controlled-release hydrogel and a preparation method thereof. A primary carrier is prepared from sodium alginate as natural polysaccharide and is coated with a glucosamine oligosaccharide layer and a sodium alginate hydrogel layer at an interval, and themultilayer coated drug-loading hydrogel is constructed. The multilayer coated drug-loading controlled-release hydrogel can be applied to the growing process of tobacco plants, by means of controlled-release glucosamine oligosaccharide, the tobacco plants are induced to produce resistance to tobacco virus diseases, tobacco virus infection and secondary infection are effectively prevented, tobacco plant cells are activated, physiological metabolism of the tobacco plants is adjusted, resistance of the tobacco plants is induced, growth of the tobacco plants is promoted, and effects of inducing virus resistance of plants f