After harvesting the mushrooms, remove the stalks with mud roots and immediately immerse them in clean water or 0.6% salt water. Mechanical injury shall be strictly prevented during picking and transportation; If it cannot be quickly transported back to the factory for processing within 3h after harvest, it must be soaked with 0.6% brine; Or use 0.03% sodium pyrosulfite solution to wash, soak and transport to prevent mushrooms from emerging. If the mushroom is soaked in 0.1% sodium pyrosulfite solution for 5-10 min in the production area, picked up and packed in a film bag, packed in a box, and transported back to the factory, it can be put into production only after 30 min of rinsing.