The invention relates to an agricultural composition containing chitosan oligosaccharide and fipronil, the agricultural composition is characterized by also containing one or a plurality of component from an insecticidal component, a sterilization component, a plant growth regulator and a fertilizer component, the insecticidal component is selected from one or a plurality of component of abamectin, chlorpyrifos, fosthiazate, thiamethoxam, phoxim, spinosad, isazofos, ivermectin, profenofos, thiodicarb and imidacloprid, the sterilization component is selected from one or a plurality of component of ethylicin, azoxystrobin, fludioxonil, hymexazol, difenoconazole and propiconazole, the plant growth regulator is selected from one or a plurality of component of mepiquat chloride, naphthylacetic acid, chlormequat chloride, uniconazole, paclobutrazol and indolebutyric acid, and the fertilizer component is selected from one or a plurality of component of nitrogen, phosphorus, potassium, calcium, magnesium, boron, zinc and amino acids. The agricultural composition can be one of a granule agent, a microcapsule agent, an absorbent product, a water agent, a water emulsion agent, a suspending agent, a water dispersible granule agent, a wettable powder agent and a microemulsion agent, and is used for root irrigation, sprinkling and pouring, furrow application pesticide-clay mixture or hole application, and the agricultural composition is used for the control of plant diseases and insect pests and regulation of plant growth.