Pleurotus ostreatus is susceptible to contamination with various degrees of bacteria during cultivation. Especially in the high temperature season, the pollution is even more serious. The use of a large number of bactericidal drugs to prevent the contamination of germs not only increases the cost, but also has little success and even leads to phytotoxicity. After many years of practice, some mushroom farmers have used methods such as covering sediment to treat bacteria. No need to apply pesticides, the operation is simple and easy, and the effect is very obvious. The specific method is: Large-bed cultivated pleurotus, if the material surface is sporadic The bacteria can be controlled by smearing or covering the contaminated area with concentrated lime slurry. If there are a lot of bacteria, you can dig up the river silt or yellow mud below 30 cm from the surface, add 2% lime powder after mixing and mix evenly, cover the 2-3 cm thick sediment on the surface of the material, cover The area is slightly larger than the contaminated area. When the material surface is heavily contaminated, sediment should be covered on the entire surface of the material. After the bags of Pleurotus ostreatus are contaminated with germs, they will be picked out by bacterial bags contaminated with bacteria, and a 60-cm pit will be dug in the place where the topography is high, and the contaminated parts of the bags will be placed downwards into the pits. The bacteria bags are 5 cm apart from each other, filled with soil, and covered with 25-30 cm thick wet fine soil or wet sand on the bacteria bags. In the rainy days, it is impossible to collect water in the membrane pits. After 15-20 days, the hyphae grow to a good length and move to the mushroom farm to open bags and produce mushrooms.