Abstract: The relative effect of freeze-thaw on the pre-treatment process of carrot slices was conducted at the puffing process. Four factors including freezing temperature, freezing time, thawing temperature, freeze-thaw frequency and the compound synergy were tested on carrot slices under the same puffing conditions by explosion puffing drying technology. Among the tests, the effect of four factors had been analyzed and the parameters of freeze-thaw processing about carrot slices had been optimized. The results showed that freezing temperature and freezing time had significant influences on friability (p <0.05) , thawing frequency had significant impact on friability, the optimized parameters of freezing and thawing processing were at the freezing temperature-18℃ for 120min then at the thawing temperature of (80±2) ℃ for once, the puffed carrot slices showed a better quality, the friability was 211.1N/s, L* value was 46.99.