The invention relates to a bactericidal composition containing pydiflumetofen and oxine-copper. The compound preparation is mainly prepared from pydiflumetofen and oxine-copper, and can be prepared into water dispersible granules and suspending agent spray. Indoor bacteriostasis and field test determination show that the compound preparation has a very good prevention and treatment effect on applealternaria leaf spot disease bacteria. The dosage form is environment-friendly in processing, high in selectivity and simple to use, and has extremely high operability and practical application value.