A bactericide composition. The composition comprises two active ingredients A and B. The active ingredient A is benziothiazolinone, the active ingredient B is flutriafol, and the two ingredients are in a weight ratio of 1:30-30:1. Further provided are a preparation method and use of the composition. The test results show that the described bactericide composition has an obvious synergistic effect, and more importantly, the application amount is reduced, and the use cost is reduced. The bactericide composition can effectively prevent and treat some specific fungal diseases of crops. Compounding bactericides with different action mechanisms and action modes effectively reduces the application amount of each single reagent, and has good effects on expanding bactericidal spectrum and delaying development of drug resistance of fungus and improving prevention and treatment effect.