Provided is a bactericide composition, said composition including two active ingredients, A and B, active component A being a compound having the structure of formula (I), active component B being mandipropamid, the weight ratio of the two components being 10-1:1-30. Also provided are a preparation method for the composition and a use of the composition. Test results show that the bactericidal composition provided in the present invention has significant synergy and, more importantly, reduced application amounts and decreased usage costs. The present bactericidal composition effectively prevents and treats certain bacteria or fungal diseases of corps. By compounding bactericides having different mechanisms and modes of action, the bactericidal spectrum is expanded, fungi and bacterial resistance are delayed, and the prevention and treatment effect is improved.
