Abstract: In order to inhibit the volatilization of tea tree essential oil and enhance its sustained release effect, tea tree essential oil microcapsules were prepared by ion gel method with tea tree essential oil as core material and sodium alginate as wall material. On the basis of clarifying the effects of single factor such as sodium alginate mass fraction, Tween-80 volume fraction, calcium chloride mass fraction and core-wall mass ratio on the embedding rate, the preparation process was optimized by response surface method. Tea tree essential oil microcapsules were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), and their sustained release properties were determined. The results showed that the optimum preparation conditions of tea tree essential oil microcapsules were as follows: the mass fraction of sodium alginate, the volume fraction of Tween-80 and the mass fraction of calcium chloride were 1.5%, 0.2% and 1.4%, respectively. The mass ratio of core to wall was 2∶1. The tea tree essential oil microcapsules prepared under these conditions had round shape, no tailing, high strength and full shape, and the embedding rate could reach 79.12%. At the same time, it had good sustained release effect. The results of FTIR and XRD analysis showed that sodium alginate was combined with tea tree essential oil through electrostatic interaction and successfully embedded it to play a protective role. Therefore, the microcapsule preparation process is simple and the embedding effect is good, which greatly improves the stability of tea tree essential oil. This study provides a technical reference for the application of tea tree essential oil microcapsules prepared by ion gel method in the post-production of agricultural products and food antibacterial preservation, which is helpful for the promotion of tea tree essential oil in the field of food industry.