Abstract: Sweet potato starch was enzymed by medium-temperature α-amylase in order to reduce the starch content.Optimized hydrolysis conditions by response surface methodology, and the obtained optimum hydrolysis conditions were used in potato pressure puffing process, aimed to obtain a better sweet potato pressure puffing process.The best hydrolysis conditions of mesophilic α-amylase hydrolysis sweet potato starch optimized by response surface methodology were:the ratio of material to liquid was1∶4, pH was 6.3, the enzymolysis temperature was 66℃, the enzymolysis time was 60min, the adding amount of enzyme was 0.95%.When the technological parameters of the sweet potato of explosion puffing were that the pressure difference was 0.4MPa, the sweet potato chips thickness was 2 ~ 3mm, the puffing temperature was 100℃, the dwell time was 10min, the vacuum temperature was 90⁹5℃, the vacuum time was 2h.The expansion frangibility and rate of water recovery of the enzyme treatment were better than the non-enzyme treatment.