Abstract: The microwave-assisted technology for extracting polysaccharide from Opuntia Milpa Alta was studied, compared with hot reflux extraction. The optimum conditions of microwave-assisted extraction were obtained by orthogonal experiment. Results are as follows: extracted with water for two times, every time for 3 min, the ration of material to solvent is 1∶10(w/v), microwave power is 700 W. The polysaccharide is deposited by 70% ethanol. The yield and content of polysaccharide are 6.8% and 8.5% respectively for microwave-assisted extraction. The yield and content of polysaccharide extracted by hot reflux technology are 4.7% and 8.3% respectively, which are lower than that of microwave-assisted extraction. The microwave-assisted extraction technology can shorten the extraction time, reduce the consumption of the solvent and improve the yield of Oputia polysaccharide.