Pesticide for killing agricultural pests as well as preparation method and application of pesticide

The invention relates to a novel camptothecin micelle, a pesticide obtained by combining the camptothecin micelle with another pesticide, and preparation methods, and further relates to a specific compound, a preparation method of the specific compound, and application of the specific compound in pesticides. The preparation method of the camptothecin micelle comprises the following steps: dissolving mPEG2000-COOH in dry methylene chloride, and then sequentially adding camptothecin, 4-dimethylamino pyridine and N,N-diisopropylcarbodiimide for a reaction; after the reaction is finished, carrying out organic phase drying treatment, filtration, distillation and spin drying to obtain a crude product; carrying out purification, adding the purified product into DMSO, and carrying out dialysis to obtain the camptothecin nano-micelle. Compared with camptothecin, the acetamiprid-coated CPT-mPEG2000 micelle formed by coating acetamiprid is higher in water solubility and toxic activity.