Taking chitosan and sodium alginate as wall materials, cinnamon oil as the core material, alginate-chitosan microcapsules were prepared through the complex coacervation method, and applied to preservation of fruits. Optical microscope (OM), Scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the technological parameters, core-wall ratio and added quantity of microcapsules. The preservation effect of chitosan solution with the different added quantity of microcapsule was analyzed, using mango as the experiment object. When chitosan/sodium alginate concentration ratio was 1:2, calcium chloride dosage was 1% , pH was 5, glutaraldehyde dosage was 60%, crosslinking time was 60 min, and core-wall mass ratio was 4:1, smooth chitosan microcapsules were prepared. When the content of microcapsules in chitosan solution was 4%, the preservation effect of mango was the best. The microencapsulation of cinnamon essential oil could effectively reduce the odor and delay volatilization, with important practical significance in the preservation of fruits and vegetables.