The invention discloses a graphene pesticide compound and a preparation method thereof. The compound comprises the following ingredients (by weight): 0.01-10% of graphene, 20-60% of a bactericide, 5-20% of a dispersant, 0-50% of a filler, 0-30% of a wetting agent, 0-10% of a disintegrating agent, 0-8% of a binder, 0-10% of an antifoaming agent, 0-30% of a thickening agent, and 0-10% of an antifreeze agent; or comprises the following ingredients (by weight): 0.01-10% of graphene, 20-50% of a bactericide, 0.1-10% of an antifoaming agent, 0.1-10% of a thickening agent, 10-20% of an antifreeze agent, 0-5% of a stabilizing agent, 10-30% of a solvent, 10-30% of an emulsifier, and 10-20% of a co-emulsifier. The prepared compound can stably adhere to the surface of crops so as to guarantee application efficiency of pesticides. Meanwhile, insect prevention efficiency can be obviously raised, dosage of pesticides is greatly reduced, bacteriocidal spectrum can be widened, and sterilization efficiency is enhanced.