In summer, cultivation of Pleurotus ostreatus in bag materials may result in the death of a large number of young mushrooms after fruiting. The main reasons are three things: First, the temperature is too high. After the formation of the primordium of Pleurotus ostreatus, if the continuous high temperature above 30 °C, the cap will gradually wither, causing a large number of young mushroom death. The second is the humidity is too large or too small. After the formation of young buds of Pleurotus ostreatus, if the relative humidity in the mushroom shed is less than 80%, the young mushroom will die due to lack of water. If Pleurotus ostreatus fruiting body during the expansion of excessive water, easy to edema and yellow ulceration. The third is poor ventilation. In case of poor ventilation in the mushroom shed, it is easy to form a "bigfoot mushroom" with a large fist or a thick handle. Therefore, the summer cultivation of Pleurotus ostreatus should pay special attention to temperature and humidity, if the temperature during the mushrooming is too high, can be used to spray cooling water wells, and to enhance ventilation and ventilation, to ensure fresh air within the mushroom shed.