The invention discloses a microbial pesticide for preventing and controlling prodenia litura. In the microbial pesticide, the prodenia litura larva, prodenia litura nuclear polyhedrosis virus production strain stock solution and fresh tobacco are used as major raw materials, and virus reproduction is performed. The microbial pesticide is prepared mainly by the following steps of: breeding the larva, inoculating the viruses, collecting the larva died of illness and performing crude extraction and filtration to obtain the virus stock solution; mixing the virus stock solution, glycerin and water at a weight ratio of 1:(1.2-4):(2.3-6) to prepare a virus stabilizer; preparing a virus mixture from the virus stock solution and 5% emamectin benzoate at a weight ratio of 1:(1.1-1.25); mixing and dissolving the virus stabilizer and the virus mixture; and adjusting the pH value to 6.8 with dilute sulphuric acid solution to obtain the microbial pesticide. The microbial pesticide disclosed by the invention is used for preventing and controlling the prodenia litura pests on crops such as vegetables, tobacco and the like, has high efficiency and environmental protection effect, and improves the quality and yield of the tobacco.