Spray drying technology was used to study the effect of different preparation conditions on the microencapsulation of onion essential oil. Taking Arabia gum and beta cyclodextrin as wall materials, the encapsulation rate as the index, the preparation process of microcapsules was optimized by response surface analysis. The content of thiosulfate (TS) in onion essential oil before and after spray drying was compared, and the extraction of onion essential oil microcapsules was also determined. The preparation technology of microcapsules was analyzed. The in vitro simulation experiment was carried out on microcapsules, and the volatilization rate of onion essential oil in microcapsules at different storage temperatures was studied. The release effect and stability of microcapsules were analyzed. The results showed that the best preparation conditions of microcapsule were emulsification temperature 61 ℃, inlet air temperature 177 ℃, feed flow 900 mL/h. Under these conditions, the encapsulation rate of microcapsule was 92.06%, and the TS retention rate of onion essential oil was similar to that of theoretical value after spray drying. The yield, moisture content, density, particle size and sensory score of microcapsule were 22.34%, 3.12%, 0.79 g/cm³, 15.3 μm, 92, respectively. The release process of onion essential oil microcapsules fitted well with Avramis formula. With the increase of temperature, the release rate constant ofmicrocapsules increased, and microcapsules should be stored at low temperature.