The invention relates to a sustained-release granular formulation for preventing and treating
crop diseases and
insect pests and a preparation method thereof. The
pesticide sustained-release granular formulation comprises
bentonite, an organic modifier,
pesticide active ingredients, an
inert filler and a binding agent, and is prepared by the preparation method comprising the steps of: (1) with the
bentonite as a basic material, modifying the
bentonite by the organic modifier to obtain organic bentonite; (2) loading the
pesticide active ingredients on the organic bentonite to prepare
medicine-carrying organic bentonite; and (3) mixing the
medicine-carrying organic bentonite, the
inert filler and the binding agent proportionally, and pelleting to obtain the sustained-release granular formulation. The preparation method of the sustained-release granular formulation, provided by the invention, not only overcomes the defect of low pesticide
loading rate of the natural bentonite, but also realizes the
controlled release of the pesticide by adjusting a
chemical structure and the amount of the modifier, so that the sustained-release granular formulation is coincident with an occurrence rule of the
plant diseases and
insect pests, and the pesticide sustained-release granular formulation is used safely, reasonably, economically and effectively.