Take Alliums cepa. L. var. agrogatum Don (ACAD) essential oil as core material and β-cyclodextrin (β-CD) as wall material, the oil was embedded with β-CD. The optimal technological process to prepare the microcapsule of ACAD essential oil was optimized by response surface methodology, with embedding rate as the index and the ratio of core to wall, mixing time and mixing temperature as the factors. The results showed that under the optimized condition (the ratio of core to wall was 1∶5.6, mixing time 2 h and mixing temperature 45 ℃),the embedding rate of the microcapsule was 41.56%.