Although fisetin may exist widely in many natural herbs, its anti-OP mechanism is still unclear. The aim of this study is to explore the molecular anti-osteoporosis (OP) mechanism of fisetin based on network pharmacology and cell experiments.The target of fisetin was extracted by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). The targets of OP were obtained by DisGeNET, GeneCards and the Comparative Toxicogenomics Database, and the targets of fisetin in OP were screened by cross-analysis. The protein-protein interaction (PPI) network was constructed by STRING, and the core targets were obtained. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses on common targets via the Database for Annotation, Visualization and Integrated Discovery. Finally, an in vitro cell experiment was used to verify the anti-OP effect and mechanism of fisetin.There are 44 targets of fisetin related to the treatment of OP. The PPI results suggest that CTNNB1, CCND1, TP53, JUN, and AKT1 are the core targets. A total of 259 biological process, 57 molecular function and 26 cell component terms were obtained from GO enrichment analysis. The results of KEGG pathway enrichment analysis suggested that fisetin treatment of OP may be related to the Wnt signaling pathway, estrogen signaling pathway, PI3K-Akt signaling pathway and other signaling pathways. In vitro cell experiments showed that fisetin significantly increased the expression levels of ALP, collagen I, osteopontin and RUNX2 in bone marrow mesenchymal stem cells (BMSCs) (p < 0.05). Fisetin also increased the gene expression levels of Wnt3 and β-catenin (CTNNB1) in BMSCs, which indicates that fisetin can regulate the Wnt/β-catenin signaling pathway and promote the osteogenic differentiation of BMSCs.Fisetin acts on multiple targets and pathways in the treatment of OP; mechanistically, it regulates the Wnt/β-catenin signaling pathway, which promotes the osteogenic differentiation of BMSCs and maintains bone homeostasis. The results of this study provide a theoretical basis for further study on the complex anti-OP mechanism of fisetin.© 2023. The Author(s).