The invention discloses a coumoxystrobin-containing bactericidal composition. The active components are composed of a first active component coumoxystrobin and a second active component fluopicolide in a weight ratio of 1:20-20:1. The composition can be prepared into agriculturally accessible water-dispersible granules, wettable powder, suspending agents and suspended seed coatings. The invention has the advantages of reasonable components, favorable bactericidal effect and low reagent cost; and the activity and bactericidal effect of the composition are not simple superposition of activities of the components. Compared with the existing single preparation, the composition not only has obvious bactericidal effect, but also has obvious synergistic action. The composition decelerates the generation of resistance, has the advantages of low preparation residue level, no pollution for crops, and high safety, conforms to the safety requirements for pesticide preparations, and has obvious effect on preventing and treating downy mildew of vegetable, epidemic disease of vegetable, seedling-stage cataplexis of vegetable and cotton, downy mildew of fruit tree, and peronophythora.