[Objective] The aim was to find out the optimal conditions to separate polysaccharides from FRUCTUS LYCII by microfiltration and ultrafiltration membrane technology. [Method] Polysaccharides were separated and purified from FRUCTUS LYCII by combining microfiltration with ultrafiltration membrane. According to the determination results of polysaccharides, influencing factors of membrane separation were evaluated, such as operating pressure, operating temperature, liquid concentration and operating time. [Result] The optimum conditions for ultrafiltration treatment were: 0.65 MPa operating pressure, 45 ℃ operating temperature, 0.72 g/L polysaccharides concentration in raw solution, and 25 min ultrafiltration treatment before the stabilized membrane flux. The optimal conditions for microfiltration treatment were: 0.20-0.22 MPa operating pressure, 50 ℃ operating temperature, and 25 min ultrafiltration treatment before the stabilized membrane flux. [Conclusion] Compared with traditional vacuum concentration method, extracting polysaccharides from FRUCTUS LYCII by membrane separation method improved product purity, reduced energy consumption, and was suitable for industrial production of polysaccharides. [Objective] The aim was to find out the optimal conditions to separate polysaccharides from FRUCTUS LYCII by microfiltration and ultrafiltration membrane technology. [Method] Polysaccharides were separated and purified from FRUCTUS LYCII by combining microfiltration with ultrafiltration membrane. According to the determination results of polysaccharides , influencing factors of membrane separation were evaluated, such as operating pressure, operating temperature, liquid concentration and operating time. [Result] The optimum conditions for ultrafiltration treatment were: 0.65 MPa operating pressure, 45 ° C operating temperature, 0.72 g / L polysaccharides concentration in raw solution, and 25 min ultrafiltration treatment before the stabilized membrane flux. The optimal conditions for microfiltration treatment were: 0.20-0.22 MPa operating pressure, 50 ° C operating temperature, and 25 min ultrafiltration treatment before the stabilized membrane flux. with traditional vacuum concentration method, extracting polysaccharides from FRUCTUS LYCII by membrane separation method improved product purity, reduced energy consumption, and was suitable for industrial production of polysaccharides.