In agriculture, chitooligosaccharides play an important role in the fields of new biopesticides, high-efficiency biological fertilizers, crop growth regulators and nematode control. Chitooligosaccharide can be used as a new type of fertilizer for agricultural production, which is based on the effect of chitooligosaccharide itself in regulating the physiological activity of plant cells and improving the quality of crops. It can be called agricultural fertilizer additive by combining with microbial fertilizer in the actual production process. Chitooligosaccharide plays the role of growth factor. Oligosaccharides, as metabolites of microbial growth, play an important role in plant growth and immunity.