Abstract: 130 W microwave output power was continuous irradiation of fresh mushrooms for 2 ~ 5 min,with perforated PE bags,3 ℃ cryogenic refrigeration 40 days,polyphenol oxidase( PPO) was regularly measured,malondialdehyde( MDA),breathing rate,lentinan,color,weight loss and other physiological indicators. The results showed that: after 40 days,2~4 min of the microwave had little effect on weight loss and color of the mushrooms.The MDA content of mushrooms got controled obviously after 3 min of the microwave,4 min of microwave made the inhibitory effect on mushroom polyphenol oxidase and respiration rate to the best,and the content of lentinan was highest,was 0.54%,the commodity rate was up to 92%. The best conditions to make the mushrooms retain freshness was under 130 W microwave processing for 4 min,the freshness limit was 40 days.