In order to improve the utilization and the development of Pleurotus eryngii snack foods, impacts of pre-treatment process on the qualities of vacuum fried mushroom were investigated. Effects of slice modes, slice thickness, and blanched treatment were studied. The results showed that slice modes had significant effects and crisp crispness and oil content were positively correlated with slice thickness. Meanwhile, 2mm was the optimum thickness and L values were negatively correlated with the slice thickness. The blanching destroyed the polyphenol oxidase and peroxidase activities in mushroom crisps, which inhibited browning and the best treatment conditions were 95℃ and 90s.