Abstract: The present invention discloses a bactericidal composition for controlling gummy stem blight of melons. The bactericidal composition includes an active ingredient composed of Pydiflumetofen and Thifluzamide. An appropriate amount of agricultural bactericide adjuvant is added into the bactericidal composition to be prepared into a common agricultural bactericide dosage form. The two components in the present invention have no cross resistance. After combined according to a certain ratio, the two agents have an obvious synergistic effect, and have a more excellent effect of controlling fungal diseases of crops. Due to the combined use, the dose may be decreased; drug resistance of pathogenic bacteria to a single agent may be delayed; ecological damage and environmental pollution are effectively decreased; and crop yield and quality can be increased. The composition widens a disease resistance spectrum.