Taking Mesona chinensis as raw material, the polysaccharides was extracted by ultrasonic assisted enzymatic method. The effects of single factors, including the variety and the concentration of signal enzyme, the concentration of complex enzymes and the ratio, enzymolysis time, enzymolysis temperature and pH on the extraction efficiency of polysaccharides were investigated, and orthogonal experiments was used to optimize the extraction process. Results showed that the optimum conditions were as follows: concentration of complex enzyme (cellulose∶pectinase=1∶1) 5%, enzymolysis temperature 50℃, enzymolysis time 2h and pH of 7. Under these conditions, the extraction efficiency of polysaccharides reached 6.60%.