Hyperlipidemia is closely related to multiple diseases and is characterized by abnormal serum lipid profiles. The biological function of lentinan in mice and rats was studied, but the mechanism of its lipid-lowering effect was not completely clear. In this study, network pharmacological analysis, molecular docking, and molecular dynamics simulation were used to explore the potential mechanism of its lipid-lowering effect and high-fat diet (HFD) mice was used to confirm the predicted mechanism. Our results indicated that lentinan could ameliorate hyperlipidemia by regulating peroxisome proliferator-activated receptors (PPARs), sterol response element-binding protein-1 (SREBP1), and nuclear factor kappa-B (NF-κB) in the hepatic tissues of mices. Further animal experiment showed that lentinan could regulate the mRNA expressions of lipid metabolism-related genes, such as PPARα, PPARδ, PPARγ, cluster of differentiation 36 (CD36) and SREBP-1c. Moreover, lentinan supplementation could reduce the expressions of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and inducible nitric oxide sythase (iNOS). In cell model, lentinan also could inhibit oleic acid-induced lipid droplet formation and the expressions of lipid metabolism-related genes and reduced inflammatory factor expressions in HepG2 cells, which further approved the results of animal experiment. Taken together, our results suggest that lentinan can ameliorate hyperlipidemia via regulating lipid metabolism-related gene expressions and reduce obesity-induced inflammatory response. Display omitted •Lentinan alleviates hyperlipidemia by regulating peroxisome proliferator-activated receptors.•Lentinan alleviates hyperlipidemia by regulating sterol response element-binding protein-1.•Lentinan inhibits nuclear factor kappa-B activity to reduce obesity-induced inflammatory response.