The invention discloses a chitosan oligosaccharide-contained leaf spraying agent, and a production method and a use method thereof, and provides a formula of the chitosan oligosaccharide-containing leaf spraying agent. The chitosan oligosaccharide-contained leaf spraying agent adopts a water-soluble leaf spraying fertilizer with full nutritive elements is elaborately prepared through reasonable proportions according to the characteristics of nutritive ingredients required by plants, and comprises elements such as N, P, K, Mn, Zn, Fe and Cu, which are required by plant during growth; the elements are existent in the state of ions and convenient to absorb; meanwhile, the elements and chitosan oligosaccharide generate a synergistic effect, so that the elements can be better and effectively absorbed. The formula has the characteristics that the leaf spraying agent can be directly sprayed to different seedling-stage plants, has remarkable effects on plant growth, fruiting rate and the like, and increases the crop yield. The leaf spraying agent can be widely applied to crops such as fruits, vegetables, grains, tea leaves, tobaccos and flowers, and has very good development and utilization values in agriculture.