Objective To investigate the mechanism by which the Tezhi Jiegu Pills combats osteoporosis (OP), we employed UPLC-HRMS, network pharmacology, molecular docking and in-vitro experiments. Methods UPLC-HRMS was performed in conjunction with the TCMSP database to profile the chemical components of the Tezhi Jiegu Pills, and the SwissTargetPrediction platform was employed to predict putative targets of these compounds. OP-related targets were then collected by integrating GeneCards, OMIM, TTD and PharmGKB. After overlapping targets were extracted with Venny 2.1, PPI-network topology analysis together with GO and KEGG functional enrichment was conducted, and a “herb-compound-target-disease-pathway” network was constructed with Cytoscape 3.10.0. Molecular docking was carried out using AutoDock to validate the binding affinity between key compounds and hub targets. For in-vitro assays, drug-containing rat serum was prepared; CCK-8 was used to evaluate its effects on the proliferation of pre-osteoblastic MC3T3 and pre-osteoclastic RAW264.7 cells, and phenotypic validation was performed by Alizarin Red S staining and tartrate-resistant acid phosphatase (TRAP) staining. Western blot and RT-qPCR were applied to determine the expression of relevant proteins and genes. Results A total of 147 compounds and 1,215 putative targets were identified in the Tezhi Jiegu Pills. After merging with 2,284 OP-related targets, 346 overlapping targets were obtained. The core hubs—TP53, PIK3CA, PIK3R1, STAT3, SRC and AKT1—were selected, and the main active components were baicalein, isoquercitrin, ginsenoside Rg1, coniferaldehyde, apigenin 5-O-glucoside and ginsenoside Rh4. KEGG analysis revealed that the drug exerts its anti-osteoporotic effect principally via the PI3K/Akt signalling pathway, and molecular docking showed stable binding between the core compounds and the hub targets. Functionally, the drug-containing serum promoted MC3T3-E1 proliferation while suppressing RAW264.7 viability (CCK-8). Western blot further demonstrated that P-AKT, P-PI3K and the inflammatory cytokines IL-6, TNF-α and IL-1β were significantly down-regulated in RAW264.7 cells, whereas the tumour-suppressor PTEN was up-regulated (P<0.05). RT-qPCR confirmed that the mRNA levels of TP53, PIK3CA, STAT3, SRC and AKT1 were also reduced. Conclusion The Tezhi Jiegu Pills is likely to exert its therapeutic effect against OP mainly by inhibiting phosphorylated AKT and PI3K as well as pro-inflammatory cytokines, thereby modulating the PI3K/Akt signaling pathway.