Abstract: Opuntia dillenii Haw. polysaccharide microcapsules were prepared by a double emulsion solvent evaporation method using Opuntia dillenii Haw.polysaccharides as the core material and poly ( lactic-co-glycolic acid) as the wall material in this study. Single factor and orthogonal experiments were used to optimize the formulation according to encapsulation efficiency. Results showed that the optimum conditions for a high encapsulation efficiency were as follows:Opuntia dillenii Haw. polysaccharide concentration, stirring rate for the primary emulsion preparation, stirring rate for the second emulsion preparation and poly ( lactic-co-glycolic acid) concentration were 10mg /mL, 20000r /min, 8000r /min and 70%, respectively. The microcapsules obtained under these conditions presented 85.17% encapsulation efficiency. Under the scanning electron microscope, the microcapsules showed a round or nearly round morphology with smooth surface and uniform size.The stability test proved that the Opuntia dillenii Haw.polysaccharide microcapsules had good stability.