Lycium barbarum polysaccharides (LBPs) are the predominant bioactive compounds in Lycium barbarum and exhibit multiple biological activities. To explore their potential anti-neuroinflammatory effects, we screened for an optimal decolorization resin and ultrafiltration membrane by using decolorization rate, polysaccharide recovery rate, and separation time as evaluation indices. A novel method for isolating and purifying LBPs was developed by coupling macroporous ion-exchange resin chromatography with ultrafiltration membrane technology. Through this approach, LBPs-N was successfully obtained. LBPs-T were prepared through conventional water extraction/alcohol precipitation and hydrogen peroxide-induced oxidative decolorization. The composition and structural characteristics of both LBPs-N and LBPs-T were analyzed using high-performance gel permeation chromatography and pre-column derivatization high-performance liquid chromatography. Their anti-neuroinflammatory activities were evaluated via the Griess method and ELISA. LX-360 resin provided optimal decolorization performance, achieving respective decolorization rates and polysaccharide recoveries of 85.64% and 80.83%. The optimum ultrafiltration membrane molecular weight was 5.0 kDa, with a polysaccharide recovery of 73.54%. LBPs-N is primarily composed of glucose, galactose, and arabinose, whereas LBPs-T predominantly consist of galactose and arabinose. Although LBPs-N and LBPs-T exhibit distinct differences in polysaccharide purity, molecular weight distribution, and triple-helix conformation, both fractions significantly suppress proinflammatory cytokine secretion, thereby alleviating lipopolysaccharide-induced microglial inflammation. Notably, LBPs-N demonstrated stronger inhibition of TNF-α, IL-6, and IL-1β. The novel method for isolating and purifying LBPs established in this study provides a theoretical foundation for their potential application in mitigating neurodegenerative diseases.