The invention relates to a microbial pesticide for preventing and treating powdery mildew of strawberry. The microbial pesticide comprises a component A, a component B and a component C, wherein the component A is composed of camphor, rheum officinale, cumin, szechwan Chinaberry fruit and auxiliary materials, the component B is composed of cinnamon oil, sandalwood oil, nepeta oil, cassia twig oil, fructus forsythiae oil, blumea oil, eugenol, cassia oil, safflower oil, costus oil, thyme oil, rosemary oil, black pepper oil and dalbergiae odoriferae oil, the component C is composed of rhizoma atractylodis, poria cocos, pinellia ternate, pericarpium citri reticulatae and radix angelicae, and the weight ratio of the component A to the component B to the component C is 1 to (1.5-2.8) to (2.2-3). The microbial pesticide has a synergistic effect through mixing of the multiple components, belongs to a pesticide with effects of killing insects, mites and fungi, can be used for preventing and treating diseases and insects for vegetables and fruit trees, has no harm to crops, is free of residues and free of pollution to the environment and the agricultural products, does not kill the natural enemies, is free of harm causing teratogenesis, cancer and mutation to mammals, is strong in lethal effect for insects, and is efficient, safe and good in prevention effect.